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A019287 Let sigma_m (n) be result of applying sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m (n) = k*n; sequence gives the (2,10)-perfect numbers. 0
480, 504, 13824, 32256, 32736, 1980342, 1396617984, 3258775296, 14763499520, 38385098752 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See also the Cohen-te Riele links under A019276.

No other terms < 5x10^11. - Jud McCranie, Feb 08 2012

LINKS

Table of n, a(n) for n=1..10.

G. L. Cohen and H. J. J. te Riele, Iterating the sum-of-divisors function, Experimental Mathematics, 5 (1996), pp. 93-100.

CROSSREFS

Sequence in context: A108256 A262222 A115157 * A258551 A257415 A179667

Adjacent sequences:  A019284 A019285 A019286 * A019288 A019289 A019290

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Jud McCranie, Nov 13 2001; a(9) Jan 29 2012, a(10) Feb 08 2012

STATUS

approved

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Last modified July 21 02:02 EDT 2019. Contains 325189 sequences. (Running on oeis4.)