A281298 a(n) is the n-th decimal digit from the right in n^n.

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

Offset

1,9

Comments

If 2 <= n <= 7, n^n has fewer than n digits, so a(n) is taken to be 0.

a(n) = 0 if n is divisible by 10.

Links

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

Example

8^8 = 16777216 so a(8) = 1.

Maple

seq(10^(1-m)*((m &^m mod 10^m) - (m &^ m mod 10^(m-1))), m=1..1000);

Prog

(Python)
def a(n): return pow(n, n, 10**n)//10**(n-1)
print([a(n) for n in range(1, 101)]) # Michael S. Branicky, Jun 21 2022

Crossrefs

Cf. A000312.

Sequence in context: A181977 A199659 A201584 * A373308 A095123 A019691

Adjacent sequences: A281295 A281296 A281297 * A281299 A281300 A281301

Keyword

nonn,base

Author

Robert Israel, Jan 19 2017

Status

approved