A111395 First digit of powers of 5.

1, 5, 2, 1, 6, 3, 1, 7, 3, 1, 9, 4, 2, 1, 6, 3, 1, 7, 3, 1, 9, 4, 2, 1, 5, 2, 1, 7, 3, 1, 9, 4, 2, 1, 5, 2, 1, 7, 3, 1, 9, 4, 2, 1, 5, 2, 1, 7, 3, 1, 8, 4, 2, 1, 5, 2, 1, 6, 3, 1, 8, 4, 2, 1, 5, 2, 1, 6, 3, 1, 8, 4, 2, 1, 5, 2, 1, 6, 3, 1, 8, 4, 2, 1, 5, 2, 1, 6

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Formula

a(n) = A000030(A000351(n)). - Seiichi Manyama, Jul 15 2023

Mathematica

First[IntegerDigits[#]]&/@(5^Range[0, 100]) (* Harvey P. Dale, Jan 13 2015 *)

Prog

(PARI) a(n) = digits(5^n)[1]; \\ Michel Marcus, Jan 07 2014

Crossrefs

Cf. A008952, A060956.

Cf. A000030, A000351, A008566.

Sequence in context: A030357 A212879 A276524 * A188596 A199622 A156730

Adjacent sequences: A111392 A111393 A111394 * A111396 A111397 A111398

Keyword

easy,nonn,base

Author

Almerio A. Castro (almerio.castro(AT)gmail.com), Nov 11 2005

Extensions

a(0)=1 prepended, and more terms from Michel Marcus, Jan 07 2014

Status

approved