A026895 T(2n,n+2), T given by A026780.
1, 7, 38, 191, 935, 4547, 22166, 108790, 538668, 2692996, 13594954, 69281309, 356222591, 1846781939, 9647229202, 50744420578, 268591503348, 1429730471552, 7649564591070, 41117462702680, 221938325574492, 1202501072716220
Offset: 2