A340618 Numbers k such that A316650(k) is prime.

13, 15, 19, 23, 31, 33, 35, 37, 43, 47, 51, 52, 59, 73, 78, 85, 93, 94, 97, 99, 105, 106, 109, 113, 115, 119, 127, 129, 139, 141, 149, 159, 163, 165, 168, 169, 179, 181, 189, 199, 211, 213, 218, 231, 232, 237, 245, 251, 256, 258, 259, 271, 273, 274, 275, 294, 301, 303, 304, 307, 339, 344, 347, 348

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(4) = 23 is a term because A316650(23) = 43 is prime.

Maple

f:= proc(n) local a, b, c;
  c:= convert(convert(n, base, 10), `+`);
  a:= floor(n/c);
  b:= n mod c;
  10^(1+ilog10(b))*a+b;
end proc:
select(n -> isprime(f(n)), [$1..100]);

Crossrefs

Cf. A316650.

Sequence in context: A166533 A166534 A126727 * A257492 A067912 A140646

Adjacent sequences: A340615 A340616 A340617 * A340619 A340620 A340621

Keyword

nonn,base

Author

J. M. Bergot and Robert Israel, Jan 15 2021

Status

approved