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 A264725 Numbers n such that the concatenation of the first n digits of the digital expansion of 1/137 is prime. 0
 3, 11, 371, 1123, 8203, 11899, 16019 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No further terms through 5000. a(n) == 3 mod 8 for all n. If m <> 3 mod 8, then the concatenation of the first m digits is either even or a multiple of 3. - Chai Wah Wu, Nov 24 2015 REFERENCES Clifford A. Pickover, A Passion for Mathematics, John Wiley & Sons, Inc., 2005, p. 88. LINKS MATHEMATICA Select[Range[2000], PrimeQ[FromDigits[PadRight[{}, #, {0, 0, 7, 2, 9, 9, 2, 7}]]]&] PROG (Python) from sympy import isprime A264725_list, c, n, m, k = [], 3, 7, 29927007, 10**8 for i in range(1, 50): if isprime(n): A264725_list.append(c) c += 8 n = n*k+m # Chai Wah Wu, Nov 24 2015 CROSSREFS Sequence in context: A097423 A111130 A337415 * A088579 A344946 A006938 Adjacent sequences: A264722 A264723 A264724 * A264726 A264727 A264728 KEYWORD nonn,base,more AUTHOR Harvey P. Dale, Nov 22 2015 EXTENSIONS a(5)-a(7) from Chai Wah Wu, Nov 24 2015 STATUS approved

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Last modified December 3 15:03 EST 2022. Contains 358534 sequences. (Running on oeis4.)