A365707 - OEIS

A365707

Initial digit of n^(n+1) (A007778(n)).

0, 1, 8, 8, 1, 1, 2, 5, 1, 3, 1, 3, 1, 3, 1, 6, 2, 1, 7, 3, 2, 1, 7, 4, 3, 2, 1, 1, 9, 7, 6, 5, 4, 4, 3, 3, 3, 3, 4, 4, 4, 5, 6, 7, 9, 1, 1, 1, 2, 3, 4, 6, 8, 1, 1, 2, 4, 6, 1, 1, 2, 4, 8, 1, 2, 4, 8, 1, 2, 5, 1, 1, 3, 7, 1, 3, 6, 1, 2, 6, 1, 3, 7, 1, 3, 8, 2

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

OFFSET

0,3

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = floor((n^(n+1))/10^floor(log_10(n^(n+1))).

a(n) = A000030(A007778(n)).

EXAMPLE

a(3) = 8, since 3^(3+1) = 3^4 = 81.

MAPLE

seq(convert(n^(n+1), base, 10)[-1], n=0..100); # Robert Israel, Feb 16 2024