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A006041 a(n+1) = (n^2 - 1)*a(n) + n + 1.
(Formerly M1949)
1
0, 2, 9, 76, 1145, 27486, 962017, 46176824, 2909139921, 232731193690, 23040388175321, 2764846581038532, 395373061088510089, 66422674262869694966, 12952421481259590518385, 2901342411802148276118256, 739842315009547810410155297, 213074586722749769398124725554, 68823091511448175515594286353961 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
REFERENCES
R. K. Guy, personal communication.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
FORMULA
Nearest integer to BesselI(1, 2)*(n-1)!*(n-1)!*n/(n-1), n>2.
MATHEMATICA
Join[{0, 2}, Table[Floor[BesselI[1, 2]*(n - 1)!*(n - 1)!*n/(n - 1)], {n, 3, 50}]] (* G. C. Greubel, Aug 16 2017 *)
RecurrenceTable[{a[1]==0, a[n+1]==(n^2-1)a[n]+n+1}, a, {n, 20}] (* Harvey P. Dale, May 16 2020 *)
PROG
(PARI) a(n) = if (n==1, 0, (n^2-2*n)*a(n-1) + n); \\ Michel Marcus, Aug 16 2017
CROSSREFS
Sequence in context: A006059 A277406 A182947 * A192551 A121131 A166891
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from James A. Sellers, May 01 2000
STATUS
approved

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Last modified February 21 22:50 EST 2024. Contains 370239 sequences. (Running on oeis4.)