#2957: A Crossword Puzzle

[A square 15x15 crossword puzzle is shown. Only 21 of the 225 squares are black. The black squares are in a pattern that are 180 degree rotationally symmetrical. Three black squares down from the 11th column and similarly three black squares up from the 5th column. Three black squares out from the right in row 7 and then two more black squares diagonally up from the end. Similarly three black squares out from the left in row 9 with two more black squares diagonally down from the end. A single black square is three above the first black square on the diagonal going down to the right and similarly there is a black square three under the first of the diagonal squares going down to the left. (Row 6 column 12 and Row 10 column 4). Finally there are three black squares on a diagonal crossing over the central point by going up from the left through the central point (Row 8 column 8). There are numbers at the top of every column (except the one that is a black square) and similarly at the left edge of all rows (except the one that is a black square). There are also numbers at the bottom of every black segment (except the one that reaches the bottom) and all rows after black segments except the one that reaches the right edge. In total all numbers from 1 to 51 are written. They are written in reading order from 1 to 51.]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

[Below the square there are two columns of clues for each number that belongs to across (rows) and to the right there is one column of clues for each number that belongs to down (columns). Both segments have an underlined and bold title above the clues. ]

Across

1. Famous Pvt. Wilhelm quote

11. IPv6 address record

15. "CIPHERTEXT" decrypted with Vigenère key "CIPHERTEXT"

16. 8mm diameter battery

17. "Warthog" attack aircraft

18. Every third letter in the word for "inability to visualize"

19. An acrostic hidden on the first page of the dictionary

21. Default paper size in Europe

22. First four unary strings

23. Lysine codon

24. 40 CFR Part 63 subpart concerning asphalt pollution

25. Top bond credit rating

26. Audi coupe

27. A pair of small remote batteries, when inserted

29. Unofficial Howard Dean slogan

32. A 4.0 report card

33. The "Harlem Globetrotters of baseball" (vowels only)

34. 2018 Kiefer song

35. Top Minor League tier

36. Reply elicited by a dentist

38. ANAA's airport

41. Macaulay Culkin's review of aftershave

43. Marketing agency trade grp.

44. Soaring climax of Linda Eder's Man of La Mancha

46. Military flight community org.

47. Iconic line from Tarzan

48. Every other letter of Jimmy Wales's birth state

49. Warthog's postscript after "They call me mister pig!"

50. Message to Elsa in Frozen 2

51. Lola, when betting it all on Black 20 in Run Lola Run

Down

1. Game featuring "a reckless disregard for gravity"

2. 101010101010101010101010_2→16

3. Google phone released July '22

4. It's five times better than that other steak sauce

5. ToHex(43690)

6. Freddie Mercury lyric from Under Pressure

7. Full-size Audi luxury sedan

8. Fast path through a multiple choice marketing survey

9. 12356631 in base 26

10. Viral Jimmy Barnes chorus

11. Ruby Rhod catchphrase

12. badbeef + 9efcebbb

13. In Wet Leg's Ur Mum, what the singer has been practicing

14. Refrain from Nora Reed bot

20. Mario button presses to ascend Minas Tirith's walls

24. Vermont historic route north from Bennington

26. High-budget video game

28. Unorthodox Tic-Tac-Toe win

29. String whose SHA-256 hash ends "...689510285e212385"

30. Arnold's remark to the Predator

31. The vowels in the fire salamander's binomial name

32. Janet Leigh Psycho line

34. Seven 440Hz pulses

37. Audi luxury sports sedan

38. A half-dozen eggs with reasonably firm yolks

39. 2-2-2-2-2-2 on a multitap phone keypad

40. .- .- .- .- .- .-

42. Rating for China's best tourist attractions

43. Standard drumstick size

45. "The rain/in Spain/falls main-/ly on the plain" rhyme scheme