A220528 - OEIS

A220528

a(n) = n^7 + 7*n + 7^n.

1, 15, 191, 2551, 18813, 94967, 397627, 1647135, 7862009, 45136639, 292475319, 1996813991, 13877119093, 96951759015, 678328486451, 4747732369423, 33233199005169, 232630924325999, 1628414210130607, 11398896079245015, 79792267577612141, 558545865884372695

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..21.

Index entries for linear recurrences with constant coefficients, signature (15,-84,252,-462,546,-420,204,-57,7).

FORMULA

a(n) = A001015(n) + A008589(n) + A000420(n).

G.f.: (55*x^8+546*x^7+8966*x^6+14692*x^5+6726*x^4-694*x^3-50*x^2-1) / ((x-1)^8*(7*x-1)). - Colin Barker, May 09 2013

EXAMPLE

a(1) = 1^7 + 7*1 + 7^1 = 15.

a(2) = 2^7 + 7*2 + 7^2 = 191.