A049301 Numbers k such that k is a substring of 3^k.

7, 9, 24, 28, 57, 61, 62, 69, 71, 72, 77, 78, 80, 83, 87, 89, 95, 111, 162, 170, 174, 185, 191, 218, 222, 225, 229, 232, 249, 255, 259, 266, 267, 286, 288, 298, 314, 315, 322, 328, 329, 330, 332, 338, 351, 352, 362, 373, 376, 381, 386, 387, 414, 421, 435, 438

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000244, A032740, A049302, A049303, A049304, A049305, A049306, A049307.

Programs

Mathematica

ssQ[n_]:=MemberQ[Partition[IntegerDigits[3^n],IntegerLength[n],1], IntegerDigits[ n]]; Select[Range[500],ssQ] (* Harvey P. Dale, Jul 16 2013 *)