A176471 - OEIS

A176471

Duplicate of A136404,

1, 4, 16, 36, 144, 576, 900, 3600, 14400, 32400, 44100, 129600, 176400, 705600, 1587600, 2822400, 6350400, 21344400, 57153600, 85377600, 192099600, 341510400, 768398400, 3073593600, 6915585600, 12294374400, 14428814400, 32464832400, 57715257600, 129859329600

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OFFSET

1,2

COMMENTS

Same as A136404. - Georg Fischer, Oct 12 2018

Previous name was: Highly composite square numbers for which the number of divisors increases to a record.

LINKS

Table of n, a(n) for n=1..30.

MATHEMATICA

With[{sqs=Range[10000]^2}, Union[Flatten[Table[Select[sqs, DivisorSigma[ 0, #]>n&, 1], {n, 500}]]]] (* Harvey P. Dale, Apr 28 2012 *)

t = {1}; sig = {1}; n = 1; Do[While[n++; d = DivisorSigma[0, n^2]; d <= sig[[-1]]]; AppendTo[sig, d]; AppendTo[t, n^2], {30}]; t (* T. D. Noe, Apr 30 2012 *)

CROSSREFS

Cf. A126098 (square root of these terms).

Cf. A136404. - Georg Fischer, Oct 12 2018

Sequence in context: A181795 A277285 A136404 * A046952 A318278 A293708

Adjacent sequences: A176468 A176469 A176470 * A176472 A176473 A176474

KEYWORD

dead

AUTHOR

Ethan Ward (etkewa(AT)gmail.com), Apr 18 2010

EXTENSIONS

Corrected and extended by Harvey P. Dale, Apr 28 2012

STATUS

approved