A161366 Each term is the previous term plus the number of letters in the previous number, as conventionally spelled out in Spanish.

1, 4, 10, 14, 21, 30, 37, 50, 59, 74, 88, 100, 104, 116, 131, 148, 167, 186, 204, 220, 236, 258, 282, 303, 318, 338, 361, 383, 406, 423, 446, 472, 496, 521, 540, 558, 582, 603, 618, 638, 661, 683, 706, 721, 741, 764, 789, 813, 829, 851, 875, 899, 923, 944, 970