A341735 a(n) = A007678(2*n+1).

0, 1, 11, 50, 154, 375, 781, 1456, 2500, 4029, 6175, 9086, 12926, 17875, 24129, 31900, 41416, 52921, 66675, 82954, 102050, 124271, 149941, 179400, 213004, 251125, 294151, 342486, 396550, 456779, 523625, 597556, 679056, 768625, 866779, 974050, 1090986, 1218151, 1356125

Offset: 0

Author

Scott R. Shannon and N. J. A. Sloane, Mar 07 2021

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A007678.

See A341734 for the other bisection (rescaled).

Programs

Julia

[div(n*(2*n-1)*(2*n^2-n+5), 6) for n in 0:40] |> println # Bruno Berselli, Mar 08 2021

Mathematica

Table[n (2 n - 1) (2 n^2 - n + 5)/6, {n, 0, 40}] (* Bruno Berselli, Mar 08 2021 *)

Formula

From Bruno Berselli, Mar 08 2021: (Start)

G.f.: x*(1 + 6*x + 5*x^2 + 4*x^3)/(1 - x)^5.

a(n) = n*(2*n - 1)*(2*n^2 - n + 5)/6. (End)

Extensions

More terms from Bruno Berselli, Mar 08 2021