A081951 Smallest triangular number which is one more than the product of n distinct numbers > 1.

3, 15, 55, 253, 1081, 13861, 115921, 665281, 18280081, 75479041, 2080995841, 68302634401, 924972048001, 48318396825601, 495843855091201, 31747936252032001, 791764338474869761

Offset

1,1

Comments

a(18) > 2^63. [From Donovan Johnson, May 30 2010]

Links

Table of n, a(n) for n=1..17.

Example

a(3) = 2*3*9 + 1 = 55. a(4) = 2*3*6*7 + 1 = 253.

Crossrefs

Cf. A081950.

Sequence in context: A015249 A084152 A084175 * A367520 A346542 A033853

Adjacent sequences: A081948 A081949 A081950 * A081952 A081953 A081954

Keyword

nonn

Author

Amarnath Murthy, Apr 02 2003

Extensions

More terms from Diana L. Mecum, Jul 09 2007

a(13)-a(17) from Donovan Johnson, May 30 2010

Status

approved