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A028500 12-hyperperfect numbers: n = 12*(sigma(n)-n-1) + 1. 4
697, 2041, 1570153, 62722153, 10604156641, 13544168521, 1792155938521 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(8) > 4*10^12. 7056410014866537089009269921 is also a term. - Donovan Johnson, Nov 20 2012

LINKS

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

Judson S. McCranie, A Study of Hyperperfect Numbers, Journal of Integer Sequences, Vol. 3 (2000), Article 00.1.3.

Eric Weisstein's World of Mathematics, Hyperperfect Number

CROSSREFS

Cf. A000396, A007593, A220290, A028499, A028501, A028502, A034916.

Sequence in context: A137559 A185377 A118059 * A133251 A243837 A116338

Adjacent sequences:  A028497 A028498 A028499 * A028501 A028502 A028503

KEYWORD

hard,more,nonn

AUTHOR

Jud McCranie

EXTENSIONS

a(7) from Donovan Johnson, Nov 20 2012

STATUS

approved

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Last modified December 9 12:25 EST 2016. Contains 278971 sequences.