A081620 - OEIS

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A081620

Least m with n*(n+1)/2 divisors.

1, 4, 12, 48, 144, 576, 960, 1260, 3600, 82944, 46080, 184320, 2985984, 129600, 55440, 6881280, 14745600, 58982400, 106168320, 907200, 18662400, 247669456896, 1321205760, 2494800, 207360000, 45158400, 7761600, 978447237120, 543581798400, 2174327193600, 1014686023680

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..1000

FORMULA

A000005(a(n)) = A000217(n) and A000005(k) <> n*(n+1)/2 for k < a(n).

a(n) = A005179(A000217(n)) = A005179(n*(n+1)/2).

CROSSREFS

Subsequence of A081619.

Cf. A000005, A000217, A005179.

Sequence in context: A255230 A253087 A262414 * A282023 A149376 A149377