OFFSET
1,1
COMMENTS
Conjecture: If a(n) is in A005153, then A050973(n) is in A005153. It is natural to ask if there exists a generalization of the indicator function for A005153, call it m(n), such that m(n) = 1 for n in A005153, 0 < m(n) < 1 otherwise, and m(a(n)) <= m(A050973(n)) for all n. See also A017666. - Jaycob Coleman, Sep 27 2014
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Friendly Pair.
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved