OFFSET
1,2
COMMENTS
LINKS
David A. Corneth, Table of n, a(n) for n = 1..166 (all elements below 10^100).
PROG
(PARI) isok(n) = {d = digits(n); if (vecsort(d, , 2) == d, ok = 1; while (ok, newn = sum(k=1, #d, d[k])*prod(k=1, #d, d[k]); if (! newn, return (0)); if (newn == n, return (1)); n = newn; d = digits(n); ); ); } \\ Michel Marcus, Mar 27 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
David A. Corneth, Mar 20 2015
STATUS
approved