A128226 Triangle, A004736 * A127899 (unsigned).
1, 4, 2, 7, 7, 3, 10, 12, 10, 4, 13, 17, 17, 13, 5, 16, 22, 24, 22, 16, 6, 19, 27, 31, 31, 27, 19, 7, 22, 32, 38, 40, 38, 32, 22, 8, 25, 37, 45, 49, 49, 45, 37, 25, 9, 28, 42, 52, 58, 60, 58, 52, 42, 28, 10
Offset: 1
Examples
First few row of the triangle are: 1; 4, 2; 7, 7, 3; 10, 12, 10, 4; 13, 17, 17, 13, 5; 16, 22, 24, 22, 16, 6; 19, 27, 31, 31, 27, 19, 7; ...
Programs
-
Mathematica
(* a127899U computes the unsigned version of A127899 *) a127899U[n_, k_] := If[n==k||n-1==k, n, 0]/;(1<=k<=n) a004736[n_, k_] := n-k+1/;(1<=k<=n+1) a128225[n_, k_] := a127899U[n, n](a004736[n, k] + a004736[n-1, k])/;(1<=k<=n) a128225[r_] := Table[a128225[n, k], {n, 1, r}, {k, 1, n}] TableForm[a128225[7]] (* triangle *) Flatten[a128225[10]] (* data *) (* Hartmut F. W. Hoft, Mar 13 2017 *)
Comments