A156701 a(n) = 4*n^4 + 17*n^2 + 4.

4, 25, 136, 481, 1300, 2929, 5800, 10441, 17476, 27625, 41704, 60625, 85396, 117121, 157000, 206329, 266500, 339001, 425416, 527425, 646804, 785425, 945256, 1128361, 1336900, 1573129, 1839400, 2138161, 2471956, 2843425, 3255304, 3710425

Offset: 0

Author

Reinhard Zumkeller, Feb 13 2009

Keywords

• nonn
• easy

Comments

a(n) = A087475(n)*A053755(n).

Links

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

Crossrefs

Cf. A016850, A053755, A087475, A099761.

Programs

Magma

[4*n^4+17*n^2+4: n in [0..50]]; // Vincenzo Librandi, Dec 27 2010

Mathematica

Table[4n^4+17n^2+4,{n,0,40}] (* or *) LinearRecurrence[{5,-10,10,-5,1},{4,25,136,481,1300},50] (* Harvey P. Dale, Nov 08 2017 *)

PARI

a(n)=4*n^4+17*n^2+4 \\ Charles R Greathouse IV, Oct 21 2022

Formula

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

G.f.: (-4-25*x^4-11*x^3-51*x^2-5*x)/(x-1)^5. - Maksym Voznyy (voznyy(AT)mail.ru), Jul 26 2009

E.g.f.: exp(x)*(4 + 21*x + 45*x^2 + 24*x^3 + 4*x^4). - Stefano Spezia, Jul 08 2023