A177054 Numbers k such that each of the decimal digits is a quadratic residue modulo k.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 19, 23, 33, 37, 39, 40, 41, 44, 46, 47, 49, 55, 59, 69, 74, 82, 89, 90, 91, 94, 95, 98, 99, 100, 101, 104, 106, 109, 110, 111, 114, 119, 131, 140, 141, 142, 143, 144, 145, 146, 149, 151, 155, 158, 167, 171, 174, 177, 184, 188, 190, 191, 193, 194, 197, 199, 217

Offset

1,2

Links

Table of n, a(n) for n=1..70.

Example

673 is in the sequence because L(6/673) = L(7/673) = L(3/673) = 1 where L(a/b) is the Legendre symbol of a and b, which is defined to be 1 if a is a quadratic
  residue (mod b) and -1 if a is a quadratic non-residue (mod b).

Maple

isA177054 := 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 isA177054(n) then printf("%d, ", n) ; end if ; end do: # R. J. Mathar, Dec 12 2010

Crossrefs

Sequence in context: A229991 A178156 A334294 * A247760 A247750 A051534

Adjacent sequences: A177051 A177052 A177053 * A177055 A177056 A177057

Keyword

nonn,base,less

Author

Michel Lagneau, Dec 09 2010

Status

approved