A030480 Primes with property that when squared all even digits occur together and all odd digits occur together.

2, 3, 5, 7, 17, 29, 47, 53, 67, 79, 83, 149, 151, 157, 257, 283, 457, 653, 683, 907, 1429, 1571, 1693, 1699, 2017, 2459, 2467, 2543, 2609, 2617, 2843, 2879, 2909, 2971, 4759, 5101, 5179, 5333, 6653, 6803, 6947, 6949, 7759, 8297, 9091, 9103

Offset

1,1

Comments

Primes whose squares have at most one odd digit. - Robert Israel, Oct 17 2023

Links

Robert Israel, Table of n, a(n) for n = 1..1000

Maple

filter:= proc(n) local L;
  if not isprime(n) then return false fi;
  convert(convert(n^2, base, 10)[2..-1] mod 2, set) = {0};
end proc:
filter(2):= true: filter(3):= true:
select(filter, [2, seq(i, i=3..10000, 2)]); # Robert Israel, Oct 17 2023

Mathematica

With[{upto=10^4}, Select[Prime[Range[upto]], Count[IntegerDigits[#^2], _?OddQ]<2&]] (* Paolo Xausa, Oct 18 2023 *)

Crossrefs

Cf. A030475, A030476.

Sequence in context: A178382 A360591 A289757 * A048418 A074788 A262833

Adjacent sequences: A030477 A030478 A030479 * A030481 A030482 A030483

Keyword

nonn,base

Author

Patrick De Geest

Extensions

Offset changed by Robert Israel, Oct 17 2023

Status

approved