A115650 Triangular numbers which are the sum of distinct double factorials (A006882).

1, 3, 6, 10, 15, 21, 28, 66, 105, 120, 153, 171, 435, 561, 946, 1378, 1485, 3916, 4005, 4278, 4851, 4950, 11781, 14365, 15576, 47586, 50086, 51360, 57970, 60378, 60726, 61425, 61776, 139128, 145530, 146070, 149878, 150426, 182710, 659526, 702705

Offset: 1

Author

Giovanni Resta, Jan 28 2006

Keywords

• nonn

Comments

Double factorials 0!! and 1!! are not considered distinct. Note that double factorial (n!!) is different from (n!)!.

Examples

			T(527) = 19128 = 13!! + 10!! + 7!! + 6!!.
		

Crossrefs

Cf. A006882, A115648, A115649.