A027132 a(n) = diagonal sum of right justified array T given by A027113.
1, 2, 4, 12, 27, 70, 182, 477, 1269, 3413, 9249, 25255, 69389, 191680, 532026, 1482926, 4148949, 11647260, 32797042, 92608175, 262157690, 743845685, 2115093984, 6026041793, 17199956143, 49176678286, 140824260498, 403865784020
Offset: 0