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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; internal format)
OFFSET

1,1

COMMENTS

See also the Cohen-te Reile links under A019276.

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

REFERENCES

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

LINKS

Experimental Mathematics, Home Page

CROSSREFS

Sequence in context: A025025 A108256 A115157 * A179667 A108876 A206200

Adjacent sequences:  A019284 A019285 A019286 * A019288 A019289 A019290

KEYWORD

nonn,changed

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

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

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Last modified February 17 14:19 EST 2012. Contains 206038 sequences.