A050626 Product of digits of n is a nonzero square.

1, 4, 9, 11, 14, 19, 22, 28, 33, 41, 44, 49, 55, 66, 77, 82, 88, 91, 94, 99, 111, 114, 119, 122, 128, 133, 141, 144, 149, 155, 166, 177, 182, 188, 191, 194, 199, 212, 218, 221, 224, 229, 236, 242, 248, 263, 281, 284, 289, 292, 298, 313, 326, 331, 334, 339, 343

Offset: 1

Author

Patrick De Geest, Jun 15 1999

Keywords

• nonn
• base

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007954, A028845, A028839.

Programs

Magma

[ n: n in [1..350] | s gt 0 and IsSquare(s) where s is &*Intseq(n,10) ];  // Bruno Berselli, May 26 2011

Mathematica

Select[Range[500],DigitCount[#,10,0]==0&&IntegerQ[Sqrt[Times@@ IntegerDigits[ #]]]&] (* Harvey P. Dale, Jun 09 2020 *)

PARI

is(n)=my(v=digits(n),pr=prod(i=1,#v,v[i]));pr&&issquare(pr) \\ Charles R Greathouse IV, May 19 2013