A034845 Primes of the form iii...ijjj...j, i != j.

13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 113, 199, 211, 223, 227, 229, 233, 277, 311, 331, 337, 433, 443, 449, 499, 557, 577, 599, 661, 677, 733, 773, 811, 877, 881, 883, 887, 911, 977, 991, 997, 1117, 1777, 1999, 2111

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10034 (first 1000 terms from Sean A. Irvine)

Mathematica

Select[Union[Flatten[Table[FromDigits[Join[PadRight[{}, n, m], PadRight[{}, k, q]]], {n, 3}, {m, 9}, {k, 3}, {q, {1, 3, 7, 9}}]]], IntegerDigits[#][[1]]!=IntegerDigits[#][[-1]]&&PrimeQ[#]&] (* Harvey P. Dale, Apr 06 2022 *)

Crossrefs

Cf. A235154.

Sequence in context: A334391 A334321 A379930 * A241059 A385481 A385637

Adjacent sequences: A034842 A034843 A034844 * A034846 A034847 A034848

Keyword

nonn,base

Author

Erich Friedman

Status

approved