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A097571 Numbers n such that triangular number t(n) (see A000217) = n(n+1)/2 is a product of three consecutive integers. 4
0, 3, 15, 20, 44, 608, 22736 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Replacing "three" by "two" we get A001652.

Replacing "three" by "N" we get: {15} for N = 4 and 5, {2079} for N = 6 and no solutions for N >= 7. - J. B. M. Melissen.

t(a(n)) equals x*(x+1)*(x+2) for x = [0, 1, 4, 5, 9, 56, 636]_n. - Zak Seidov, Jun 21 2013

LINKS

Table of n, a(n) for n=1..7.

S. P. Mohanty, Which triangular numbers are products of three consecutive integers?, Acta Mathematica Hungarica 1991, Volume 58, Issue 1-2, pp 31-36.

CROSSREFS

Cf. A000217, A001219, A001652.

Sequence in context: A111517 A083545 A224872 * A048087 A316751 A001897

Adjacent sequences:  A097568 A097569 A097570 * A097572 A097573 A097574

KEYWORD

nonn,fini,full

AUTHOR

N. J. A. Sloane, Aug 29 2004

STATUS

approved

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Last modified November 12 14:43 EST 2019. Contains 329058 sequences. (Running on oeis4.)