a(n) = Sum_{k=0..n} divides(k, n) * 3^k, where divides(k, n) = 1 if k divides n, otherwise 0.

A363913

a(n) = Sum_{k=0..n} divides(k, n) * 3^k, where divides(k, n) = 1 if k divides n, otherwise 0.

Terms

    a(0) =1a(1) =3a(2) =12a(3) =30a(4) =93a(5) =246a(6) =768a(7) =2190a(8) =6654a(9) =19713a(10) =59304a(11) =177150a(12) =532290a(13) =1594326a(14) =4785168a(15) =14349180a(16) =43053375a(17) =129140166a(18) =387440940a(19) =1162261470a(20) =3486843786a(21) =10460355420a(22) =31381236768a(23) =94143178830a(24) =282430075332a(25) =847288609689

External references