A367551 a(n) = Sum_{d|n} (d^2+1)^n.

2, 29, 1008, 84162, 11881408, 2566742098, 781250000128, 318651789038947, 167619551409708544, 110462353708225871026, 89116503268220597579776, 86380568889558343409300388, 99045780329059370000000008192

Offset: 1

Author

Seiichi Manyama, Nov 22 2023

Keywords

• nonn

Crossrefs

Cf. A163190, A308570, A367552.

Programs

PARI

a(n) = sumdiv(n, d, (d^2+1)^n);

Formula

a(n) = Sum_{k=0..n} binomial(n,k) * sigma_{2*k}(n).