A387525 - OEIS

A387525

a(n) = (n^4-3*n^2+4*n+2)/2.

1, 2, 7, 34, 113, 286, 607, 1142, 1969, 3178, 4871, 7162, 10177, 14054, 18943, 25006, 32417, 41362, 52039, 64658, 79441, 96622, 116447, 139174, 165073, 194426, 227527, 264682, 306209, 352438, 403711, 460382, 522817, 591394, 666503, 748546, 837937, 935102, 1040479, 1154518, 1277681, 1410442, 1553287, 1706714, 1871233, 2047366

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Paolo Xausa, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

FORMULA

From Stefano Spezia, Sep 09 2025: (Start)

G.f.: (1 - 3*x + 7*x^2 + 9*x^3 - 2*x^4)/(1 - x)^5.

E.g.f.: exp(x)*(2 + 2*x + 4*x^2 + 6*x^3 + x^4)/2. (End)

MATHEMATICA

A387525[n_] := n*(n^3 - 3*n + 4)/2 + 1; Array[A387525, 50, 0] (* or *)