1,1

See also the Cohen-te Riele links under A019276.

No further term <10^9 [see Table 1].

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

Table of n, a(n) for n=1..3.

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

Experimental Mathematics, Home Page

Sequence in context: A156239 A141369 A060390 * A284737 A323593 A013630

Adjacent sequences: A019278 A019279 A019280 * A019282 A019283 A019284

nonn,bref

N. J. A. Sloane.

approved