1,1

See also the Cohen-te Riele links under A019276.

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.

Sequence in context: A276323 A288086 A210297 * A237910 A244575 A105649

Adjacent sequences: A019285 A019286 A019287 * A019289 A019290 A019291

nonn,bref

N. J. A. Sloane.

approved