A177055 Numbers k such that each decimal digit is a quadratic non-residue modulo k.

22, 25, 26, 32, 35, 36, 38, 52, 53, 56, 63, 65, 66, 72, 75, 76, 77, 78, 85, 88, 222, 225, 228, 232, 235, 236, 237, 252, 255, 256, 258, 262, 266, 267, 268, 272, 273, 275, 276, 282, 283, 285, 286, 288, 323, 325, 332, 333, 335, 336, 352, 353, 357, 368, 372, 375, 376, 377, 385, 387, 522, 523, 525, 528, 532, 533, 535, 536

Offset

1,1

Comments

The digits 0,1,4,9 are squares, so no members of the sequence have those digits. - Robert Israel, Apr 03 2017

Links

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

Example

75 is in the sequence because neither 7 nor 5 is a square mod 75. - Corrected by Robert Israel, Apr 03 2017

Maple

isA177055 := proc(n) local d; for d in convert(n, base, 10) do if numtheory[quadres](d, n) <> -1 then return false; end if; end do; return true; end proc:
for n from 1 to 140 do if isA177055(n) then printf("%d, ", n) ; end if ; end do: # R. J. Mathar, Dec 12 2010

Crossrefs

Sequence in context: A061411 A053779 A177734 * A186780 A034304 A167459

Adjacent sequences: A177052 A177053 A177054 * A177056 A177057 A177058

Keyword

nonn,base,less

Author

Michel Lagneau, Dec 09 2010

Status

approved