A097413 - OEIS

A097413

Initial decimal digit of n^9.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Gelfand's Question

FORMULA

a(n) = A000030(n^9) = floor(n^9/10^A004216(n^9)). - Robert Israel, Jan 28 2016

EXAMPLE

1, 512, 19683, 262144, 1953125, 10077696, 40353607, 134217728, 387420489, 1000000000, ...

MAPLE

idd:= n -> floor(n/10^ilog10(n)):