A031147 Smallest power of 2 containing exactly n zeros.

1, 1024, 4398046511104, 8796093022208, 604462909807314587353088, 309485009821345068724781056, 1267650600228229401496703205376, 5070602400912917605986812821504, 784637716923335095479473677900958302012794430558004314112

Offset

0,2

Links

Table of n, a(n) for n=0..8.

Formula

a(n) = 2^A031146(n). - M. F. Hasler, Jun 15 2018 (corrected by Sean A. Irvine, Apr 11 2020)

Prog

(PARI) A031147(n)=for(k=n, oo, #select(d->!d, digits(2^k))==n&&return(2^k)) \\ M. F. Hasler, Jun 15 2018

Crossrefs

Cf. A031146.

Sequence in context: A017302 A017422 A017554 * A087932 A351310 A045035

Adjacent sequences: A031144 A031145 A031146 * A031148 A031149 A031150

Keyword

nonn,easy,base

Author

N. J. A. Sloane

Extensions

More terms from Erich Friedman

a(8) added by M. F. Hasler, Jun 16 2018

Status

approved