A375640 - OEIS

A375640

The smallest triangular number that begins a run of at least n consecutive triangular numbers with the same number of divisors.

1, 6, 6, 6, 3181503, 213118335, 21363375160, 83495980981, 595814595900153, 2153650189195351, 49340595918273751, 3380756271799042653, 13175529217290940503

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

a(4) = 6 because 6 is the smallest triangular number that begins a run of 4 consecutive triangular numbers (6, 10, 15, 21) with the same number of divisors, i.e. 4.

a(5) = 3181503 because 3181503 is the smallest triangular number that begins a run of 5 consecutive triangular numbers (3181503, 3184026, 3186550, 3189075, 3191601) with the same number of divisors, i.e. 24.

CROSSREFS

Cf. A000217, A063440, A319037, A319038.

Sequence in context: A078245 A241057 A375657 * A247253 A244293 A196737

Adjacent sequences: A375637 A375638 A375639 * A375641 A375642 A375643

KEYWORD

nonn,more,hard

AUTHOR

Shyam Sunder Gupta, Aug 22 2024

STATUS

approved