A380884 Primes p such that there is an m < 10 for which m*p contains every decimal digit of p.
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
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
Links
- Michael De Vlieger, Table of n, a(n) for n = 1..5000
Programs
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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 *)
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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