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A189001 a(n) = Sum_{i=0..n} (i+1)*n^i. 2
1, 3, 17, 142, 1593, 22461, 380713, 7526268, 169826513, 4303999495, 120987654321, 3734729768298, 125562274081225, 4566262891748481, 178581127445062553, 7473240118999870456, 333189190735802745633, 15766036084935301064139 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Bruno Berselli, Table of n, a(n) for n = 0..300

FORMULA

a(n) = ((n^2-2)*n^(n+1)+1)/(n-1)^2 for n > 1; a(0)=1, a(1)=3.

EXAMPLE

a(4) = 1593  because  1593 = 1+2*4+3*4^2+4*4^3+5*4^4.

MATHEMATICA

Join[{1, 3}, Table[(((n^2 - 2) n^(n + 1) + 1) / (n - 1)^2), {n, 2, 20}]] (* Vincenzo Librandi, Aug 19 2013 *)

PROG

(MAGMA) [&+[(k+1)*n^k: k in [0..n]]: n in [0..17]];

CROSSREFS

Cf. A031973, A051846, A062806.

Cf. A189122: Sum_{i=0..n} (i+1)^2*n^i.

Sequence in context: A062873 A120022 A001865 * A087885 A178685 A268254

Adjacent sequences:  A188998 A188999 A189000 * A189002 A189003 A189004

KEYWORD

nonn

AUTHOR

Bruno Berselli, Apr 15 2011

STATUS

approved

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Last modified October 14 14:45 EDT 2019. Contains 328019 sequences. (Running on oeis4.)