A076579 Triangular numbers which are 5-almost primes.

120, 300, 378, 496, 630, 780, 990, 1128, 1485, 1540, 1596, 2556, 2628, 2850, 3160, 3321, 3570, 3828, 4095, 4851, 5778, 5886, 6328, 6786, 7750, 8778, 9045, 9870, 10878, 11781, 12090, 13203, 13530, 14028, 14535, 14706, 15225, 16110, 16290

Offset

1,1

Links

Table of n, a(n) for n=1..39.

Example

a(1)=120, 120 is a triangular number and 120=2*2*2*3*5 i.e. is a product of 5 prime factors so is 5-almost prime.

Crossrefs

Sequence in context: A211467 A257712 A250607 * A345350 A121898 A048190

Adjacent sequences: A076576 A076577 A076578 * A076580 A076581 A076582

Keyword

base,easy,nonn

Author

Shyam Sunder Gupta, Oct 19 2002

Status

approved