A166735 Superabundant numbers (A004394) that are not highly composite (A002182).

1163962800, 4658179125600, 13974537376800, 144403552893600, 433210658680800, 10685862914126400, 21371725828252800, 32057588742379200, 37400520199442400, 64115177484758400, 1533421328177138400

Offset

1,1

Comments

Alaoglu and Erdos mention the first term in footnote 14.

Because the "shapes" of superabundant and highly composite numbers are different, there is a last superabundant number that is also highly composite. In factored form, that 154-digit number is N = A004394(1023) = A002182(2567) = 2^10 3^6 5^4 7^3 11^3 13^2 17^2 19^2 23^2 29 31 37...347. In other words, this sequence contains all superabundant numbers greater than N. - _T. D. Noe_, Oct 26 2009

Links

T. D. Noe, Table of n, a(n) for n = 1..574

L. Alaoglu and P. Erdos, On highly composite and similar numbers, Trans. Amer. Math. Soc., 56 (1944), 448-469. Errata

Thomas Fink, Recursively divisible numbers, arXiv:1912.07979 [math.NT], 2019. Mentions this sequence.

S. Ramanujan, Highly composite numbers, Proceedings of the London Mathematical Society, 2, XIV, 1915, 347 - 409.

S. Ramanujan, Highly composite numbers, Annotated and with a foreword by J.-L. Nicolas and G. Robin, Ramanujan J., 1 (1997), 119-153.

Formula

a(574+i) = A004394(1023+i) for i>0.

Crossrefs

Cf. A166981 (intersection of SA and HC numbers). - _T. D. Noe_, Oct 26 2009

Cf. A189228 (SA numbers that are not CA).

Sequence in context: A159568 A287547 A115173 * A104933 A345721 A346362

Adjacent sequences: A166732 A166733 A166734 * A166736 A166737 A166738

Keyword

nonn

Author

_T. D. Noe_, Oct 20 2009

Status

approved