login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

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