OFFSET
1,1
LINKS
Michel Marcus, Table of n, a(n) for n = 1..200
Jean-Luc Garambois, Aliquot sequences starting on integer powers 2^i
FORMULA
a(n) = A115350(2^n).
PROG
(PARI) a(n) = my(b=2); if (n==1, return(b)); my(list = List(), s=b^n); for (i=1, oo, s = sigma(s) - s; if (#select(x->(x==s), list), return(s)); if (isprime(s), return (s)); listput(list, s); );
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Nov 14 2022
STATUS
approved