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A180435 a(n) = a(n-1)*2^n+n, a(0)=1. 0
1, 3, 14, 115, 1844, 59013, 3776838, 483435271, 123759429384, 63364827844617, 64885583712887818, 132885675443994251275, 544299726618600453222412, 4458903360459574912797999117, 73054672657769675371282417532942 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..14.

FORMULA

a(n+1) = (2^(n + 1) + 1)*a(n) - 2^n*a(n - 1) + 1.

a(n+1) = ((a(n - 2) + 4*a(n - 1) + 4)*a(n) - 2*a(n - 1)^2 - 4*a(n)^2 + a(n - 2) - 4*a(n - 1))/(a(n - 2) - 2*a(n - 1)).

a(n) = 2^(n*(n+1)/2) + sum_{k=1..n} 2^( (n+k+1)*(n-k)/2 ) * k. - Max Alekseyev, Sep 05 2010

MATHEMATICA

nxt[{n_, a_}]:={n+1, a*2^(n+1)+n+1}; Transpose[NestList[nxt, {0, 1}, 20]] [[2]] (* Harvey P. Dale, Apr 05 2015 *)

PROG

(PARI) a(n)=if(n<=0, 1, a(n-1)*2^n+n )

CROSSREFS

Cf. A010842.

Sequence in context: A265001 A279429 A229113 * A256159 A122081 A007140

Adjacent sequences:  A180432 A180433 A180434 * A180436 A180437 A180438

KEYWORD

nonn

AUTHOR

Georgi Guninski, Sep 05 2010

EXTENSIONS

Minor edits by N. J. A. Sloane, Sep 05 2010

STATUS

approved

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Last modified May 26 02:35 EDT 2019. Contains 323579 sequences. (Running on oeis4.)