Antidiagonal sums of triangle A118180: a(n) = Sum_{k=0..[n/2]} (3^k)^(n-2*k) for n>=0.

A118182

Antidiagonal sums of triangle A118180: a(n) = Sum_{k=0..[n/2]} (3^k)^(n-2*k) for n>=0.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =11a(5) =37a(6) =164a(7) =1000a(8) =8021a(9) =81001a(10) =1076006a(11) =19683244a(12) =473632031a(13) =14349084877a(14) =571833704648

External references