A177009 a(n) = n^n - A002275(n).

0, -7, -84, -855, -7986, -64455, -287568, 5666105, 276309378, 8888888889, 274200559500, 8804989337145, 301763995481142, 11100895714446905, 437782779269748264, 18445632962598440505, 827229150775225653066

Offset: 1

Author

Ali Heydarian (mymontain(AT)yahoo.com), May 13 2010

Keywords

• easy
• sign
• base

Comments

20^20-11111111111111111111=104857588888888888888888889 is the only known prime term of this sequence. Next such prime has more than 40000 digits (n>10000)!

Examples

			a(2) = 2^2-11 = -7, a(8) = 8^8-11111111 = 5666105.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..386

Crossrefs

Cf. A000312, A002275, A177010.

Programs

Maple

seq(n^n - (10^n-1)/9. n=1..20); # Robert Israel, Oct 23 2016

Mathematica

Table[n^n - (10^n - 1)/9, {n, 17}]

Formula

a(n) = n^n - (10^n-1)/9. - Robert Israel, Oct 23 2016