A115904 Numbers n such that n+sigma(n) is a triangular number.

7, 10, 66, 136, 145, 196, 198, 234, 270, 438, 495, 528, 592, 606, 855, 910, 1045, 1158, 1428, 2208, 2718, 2922, 3016, 3663, 3808, 3916, 4506, 4975, 5043, 5136, 5598, 6366, 6600, 7080, 7498, 7821, 8172, 8200, 8217, 8814, 9318, 9730, 9738