Indices of the triangular numbers which are also centered triangular number.

A133161

Indices of the triangular numbers which are also centered triangular number.

Terms

    a(0) =1a(1) =4a(2) =16a(3) =61a(4) =229a(5) =856a(6) =3196a(7) =11929a(8) =44521a(9) =166156a(10) =620104a(11) =2314261a(12) =8636941a(13) =32233504a(14) =120297076a(15) =448954801a(16) =1675522129a(17) =6253133716a(18) =23337012736a(19) =87094917229a(20) =325042656181

External references