A036435 Digits are nonzero squares.

1, 4, 9, 11, 14, 19, 41, 44, 49, 91, 94, 99, 111, 114, 119, 141, 144, 149, 191, 194, 199, 411, 414, 419, 441, 444, 449, 491, 494, 499, 911, 914, 919, 941, 944, 949, 991, 994, 999, 1111, 1114, 1119, 1141, 1144, 1149, 1191, 1194, 1199, 1411, 1414, 1419, 1441

Offset: 1

Author

Simon Colton (simonco(AT)cs.york.ac.uk)

Keywords

• easy
• nonn
• base

Comments

Invented by the HR concept formation program.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• S. Colton, Refactorable Numbers - A Machine Invention, J. Integer Sequences, Vol. 2, 1999, #2.
• S. Colton, HR - Automatic Theory Formation in Pure Mathematics

Crossrefs

Cf. A046030.

Programs

Mathematica

Flatten[Table[FromDigits/@Tuples[{1,4,9},n],{n,4}]] (* Harvey P. Dale, May 18 2015 *)

PARI

isok(n) = {digs = digits(n); for (i=1, #digs, if (! digs[i] || ! issquare(digs[i]), return (0));); return (1);} \\ Michel Marcus, Aug 31 2013

Extensions

More terms from Sam Alexander (pink2001x(AT)hotmail.com).