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A270868
a(n) = n^4 + 3*n^3 + 8*n^2 + 9*n + 2.
7
2, 23, 92, 263, 614, 1247, 2288, 3887, 6218, 9479, 13892, 19703, 27182, 36623, 48344, 62687, 80018, 100727, 125228, 153959, 187382, 225983, 270272, 320783, 378074, 442727, 515348, 596567, 687038, 787439, 898472, 1020863, 1155362, 1302743, 1463804, 1639367
OFFSET
0,1
LINKS
Andrew Misseldine, Counting Schur Rings over Cyclic Groups, arXiv preprint arXiv:1508.03757 [math.RA], 2015 (page 19, 5th row; page 21, 4th row).
FORMULA
G.f.: (2+13*x-3*x^2+13*x^3-x^4)/(1-x)^5.
a(n) = 5*a(n-1)-10*a(n-2)+10*a(n-3)-5*a(n-4)+a(n-5).
From G. C. Greubel, Apr 01 2016: (Start)
a(2*m) == 0 (mod 2).
a(4*m + 2) == 0 (mod 4).
E.g.f.: (2 +21*x +24*x^2 +9*x^3 +x^4)*exp(x). (End)
a(n)+a(n+2)-2*a(n+1) = 6*A033816(n+1). - Wesley Ivan Hurt, Apr 02 2016
MAPLE
A270868:=n->n^4 + 3*n^3 + 8*n^2 + 9*n + 2: seq(A270868(n), n=0..50); # Wesley Ivan Hurt, Apr 01 2016
MATHEMATICA
Table[n^4 + 3 n^3 + 8 n^2 + 9 n + 2, {n, 0, 40}]
PROG
(Magma) [n^4+3*n^3+8*n^2+9*n+2: n in [0..40]];
CROSSREFS
Sequence in context: A069152 A131464 A245331 * A239186 A238185 A053999
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 01 2016
STATUS
approved