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A080291 a(n)=(-1)^(n+1)n^n(n+(1/12)(n^2-1)). 0
1, -9, 99, -1344, 21875, -416016, 9058973, -222298112, 6069587661, -182500000000, 5991545082831, -213243402387456, 8177627877990831, -336138206473129984, 14742427642822265625, -687141216745680797696, 33916850737339807331257 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is the determinant of the n X n matrix M with M(i,i)=2i-n, M(i.j)=i+j.

LINKS

Table of n, a(n) for n=1..17.

FORMULA

a(n)=(-1)^(n+1)n^n(n+(1/12)(n^2-1)). a(n)=(-1)^n(n^n-n^(n-1)A002378(n)-n^(n-2)A002415(n)).

MATHEMATICA

Table[(-1)^(n + 1)n^n(n + (n^2 - 1)/12), {n, 1, 17}]

CROSSREFS

Sequence in context: A294120 A015685 A051581 * A215243 A113395 A070068

Adjacent sequences:  A080288 A080289 A080290 * A080292 A080293 A080294

KEYWORD

easy,sign

AUTHOR

Mario Catalani (mario.catalani(AT)unito.it), Feb 13 2003

STATUS

approved

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Last modified May 11 18:21 EDT 2021. Contains 343808 sequences. (Running on oeis4.)