A206804 (1/2)*A206803.

1, 4, 13, 26, 49, 78, 121, 188, 264, 370, 498, 638, 804, 1012, 1265, 1534, 1854, 2210, 2585, 3020, 3497, 4040, 4675, 5358, 6066, 6826, 7613, 8456, 9502, 10608, 11807, 13038, 14434, 15864, 17399, 19042, 20759, 22590, 24538, 26526, 28719

Offset: 2

Author

Clark Kimberling, Feb 13 2012

Keywords

• nonn

Crossrefs

Cf. A206803.

Programs

Mathematica

s[k_] := Prime[k + 1]; t[1] = 0;
p[n_] := Sum[s[k], {k, 1, n}];
c[n_] := n*s[n] - p[n]
t[n_] := t[n - 1] + (n - 1) s[n] - p[n - 1]
Table[c[n], {n, 2, 100}]  (* A185382 *)
%/2  (* A206802 *)
Flatten[Table[t[n], {n, 2, 40}]]  (*  A206803 *)
%/2  (* A206804 *)