Indices of centered octagonal numbers (A016754) which are also heptagonal numbers (A000566).
A253920
Indices of centered octagonal numbers (A016754) which are also heptagonal numbers (A000566).
Terms
- a(0) =1a(1) =5a(2) =39a(3) =760a(4) =6494a(5) =55518a(6) =1095199a(7) =9363623a(8) =80056197a(9) =1579275478a(10) =13502337152a(11) =115440979836
External references
- oeis: A253920