OFFSET
4,2
COMMENTS
Conjecture: a(n) exists for all n > 3.
LINKS
Zhi-Wei Sun, Table of n, a(n) for n = 4..10000
EXAMPLE
a(5) = 19 since 5 is relatively prime to 19 and 5 + 19 = 24 divides C(5) + C(19) = 42 + 1767263190 = 1767263232 = 24*73635968.
MATHEMATICA
Do[m=1; Label[aa]; If[GCD[m, n]==1&&Mod[CatalanNumber[m]+CatalanNumber[n], m+n]==0, Print[n, " ", m]; Goto[bb]]; m=m+1; Goto[aa]; Label[bb]; Continue, {n, 4, 60}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zhi-Wei Sun, Oct 01 2014
STATUS
approved