A123656 a(n) = 1 + n^4 + n^6.

3, 81, 811, 4353, 16251, 47953, 120051, 266241, 538003, 1010001, 1786203, 3006721, 4855371, 7567953, 11441251, 16842753, 24221091, 34117201, 47176203, 64160001, 85960603, 113614161, 148315731, 191434753, 244531251, 309372753, 387951931

Offset: 1

Author

Jonathan Vos Post, Oct 04 2006

Keywords

• easy
• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

Crossrefs

Cf. A001358, A002523, A091940, A123177, A123657-A123659.

Programs

Magma

[1 + n^4 + n^6: n in [1..25]]; // G. C. Greubel, Oct 17 2017

Mathematica

Table[1 + n^4 + n^6, {n, 1, 50}] (* G. C. Greubel, Oct 17 2017 *)
LinearRecurrence[{7,-21,35,-35,21,-7,1},{3,81,811,4353,16251,47953,120051},30] (* Harvey P. Dale, May 10 2020 *)

PARI

a(n)=1+n^4+n^6 \\ Charles R Greathouse IV, Oct 07 2015

Formula

a(n) = 1 + n^4 + n^6.

G.f.: x*(3 +60*x +307*x^2 +272*x^3 +81*x^4 -4*x^5 +x^6)/(1-x)^7. - Colin Barker, May 25 2012