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A121987
a(n + 4) = (n + 2)*(a(n + 3) - a(n) + 1) for n > 3, a(0) = a(1) = a(2) = a(3) = 1.
1
1, 1, 1, 1, 2, 6, 24, 120, 714, 4963, 39520, 354609, 3538960, 38873978, 466013508, 6053565700, 84700374374, 1269922505955, 20311303879168, 345189255328973, 6211881989182800, 118001629266860074, 2359626359259618140
OFFSET
0,5
LINKS
MATHEMATICA
RecurrenceTable[{a[n + 4] == (n + 2)*(a[n + 3] - a[n] + 1), a[0] == 1, a[1] == 1, a[2] == 1, a[3] == 1}, a, {n, 0, 50}] (* G. C. Greubel, Sep 14 2017 *)
CROSSREFS
Sequence in context: A324134 A324135 A177531 * A324132 A177524 A223905
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Sep 10 2006
EXTENSIONS
Edited by N. J. A. Sloane, Jun 17 2007
Edited and name changed by G. C. Greubel, Sep 14 2017
STATUS
approved