cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A380884 Primes p such that there is an m < 10 for which m*p contains every decimal digit of p.

Original entry on oeis.org

2, 5, 41, 43, 59, 97, 191, 197, 251, 263, 373, 401, 443, 491, 499, 599, 653, 691, 967, 991, 997, 1481, 1901, 1913, 1997, 2549, 2551, 2591, 3067, 3491, 4001, 4013, 4493, 4793, 4931, 4943, 4967, 4973, 4993, 4999, 5021, 5443, 5647, 6053, 6361, 6521, 6703, 6991, 7489, 7901, 7951, 7993
Offset: 1

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Author

David James Sycamore, Feb 07 2025

Keywords

Examples

			6*2 = 12 therefore 2 is a term (m = 6 < 10).
499*6 = 2994 therefore 499 is a term (m = 6 < 10).
599*5 = 2995 therefore 599 is a term (m = 5 < 10).
37 is not a term since 10*37 = 370 is the smallest multiple of 37 containing 3 and 7
		

Crossrefs

Programs

  • Mathematica
    nn = 10000; Reap[Do[p = Prime[n]; d = DigitCount[p]; k = 2; While[! AllTrue[DigitCount[#] - d, # >= 0 &] &[p*k], k++]; If[k < 10, Sow[p]], {n, nn}]][[-1, 1]] (* Michael De Vlieger, Feb 20 2025 *)
  • PARI
    lista(nn) = forprime(p=2, nn, if (A380883(p) != 10*p, print1(p, ", "))); \\ Michel Marcus, Feb 20 2025

Extensions

59, 491, and more terms added by Michel Marcus, Feb 20 2025