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A213168 a(n) = n!/2 - (n-1)! - n + 2. 2
0, 0, 4, 33, 236, 1795, 15114, 141113, 1451512, 16329591, 199583990, 2634508789, 37362124788, 566658892787, 9153720575986, 156920924159985, 2845499424767984, 54420176498687983, 1094805903679487982, 23112569077678079981, 510909421717094399980 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

COMMENTS

Row sums of A142706 for k=1..n-1.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 2..200

FORMULA

a(n) = A001286(n-1) - n + 2. - Anton Zakharov, Sep 08 2016

MATHEMATICA

Table[n!/2 - (n - 1)! - n + 2, {n, 2, 20}]

PROG

(Maxima) A213168(n):=n!/2-(n-1)!-n+2$

makelist(A213168(n), n, 2, 30); /* Martin Ettl, Nov 03 2012 */

(MAGMA) [Factorial(n)/2-Factorial(n-1)-n+2: n in [2..25]]; // Vincenzo Librandi, Sep 09 2016

CROSSREFS

Cf. A001286.

Cf. A142706, A051683, A152883.

Cf. A200748 (considered as a triangular array).

Sequence in context: A131509 A221030 A081007 * A203212 A088317 A041024

Adjacent sequences:  A213165 A213166 A213167 * A213169 A213170 A213171

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard, Nov 02 2012

STATUS

approved

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Last modified December 6 14:15 EST 2019. Contains 329806 sequences. (Running on oeis4.)