OFFSET
1,1
COMMENTS
See also the Cohen-te Riele links under A019276.
No other terms < 5*10^11. - Jud McCranie, Feb 08 2012
36095341363200 is also a term. See comment in A019278. - Michel Marcus, May 15 2016
a(11) > 4*10^12. - Giovanni Resta, Feb 26 2020
LINKS
Graeme L. Cohen and Herman J. J. te Riele, Iterating the sum-of-divisors function, Experimental Mathematics, 5 (1996), pp. 93-100.
PROG
(PARI) isok(n) = sigma(sigma(n))/n == 14; \\ Michel Marcus, May 15 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Jud McCranie, Nov 13 2001
a(9) from Jud McCranie, Jan 28 2012
a(10) from Giovanni Resta, Feb 26 2020
STATUS
approved