A306377 a(n) = n^(n+1) - Sum_{k=1..n-1} k^(k+1).

1, 7, 72, 934, 14511, 263197, 5468126, 128156252, 3346505197, 96372936395, 3034801313116, 103751149938746, 3827141124879891, 151520483911293537, 6408792648508559714, 288419881116435604320, 13761208522825454943617, 693870384974027681319231

Offset: 1

Author

Kritsada Moomuang, Feb 11 2019

Keywords

• nonn

Examples

			a(5) = 5^6 - 4^5 - 3^4 - 2^3 - 1^2 = 14511.
		

Crossrefs

Cf. A007778, A062815.

Programs

PARI

a(n) = n^(n+1) - sum(k=1, n-1, k^(k+1)); \\ Michel Marcus, Feb 11 2019

Formula

a(n) = 2*A007778(n) - A062815(n).