A063540 Smallest k such that 2^k has exactly n 6's in its decimal representation.

1, 4, 16, 36, 60, 100, 72, 123, 124, 161, 157, 243, 196, 230, 222, 220, 300, 323, 361, 447, 378, 551, 433, 506, 555, 565, 636, 508, 606, 662, 701, 778, 810, 746, 823, 839, 850, 977, 1074, 861, 1046, 1086, 996, 1161, 1067, 1168, 1083, 983, 1223, 1252, 1303

Offset

0,2

Links

Harry J. Smith, Table of n, a(n) for n = 0..150

Mathematica

a = {}; Do[k = 1; While[ Count[ IntegerDigits[2^k], 6] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

Prog

(PARI) a(n)={my(k=1); while(n<>#select(d->d==6, digits(2^k)), k++); k} \\ Harry J. Smith, Aug 25 2009, Andrew Howroyd, Jun 26 2018

Crossrefs

Cf. A063115, A063426, A063429, A063430, A063526, A063552, A063553, A063554.

Sequence in context: A174597 A044065 A281795 * A349223 A055808 A016742

Adjacent sequences: A063537 A063538 A063539 * A063541 A063542 A063543

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 10 2001

Extensions

Name corrected by Jon E. Schoenfield, Jun 25 2018

Status

approved