

A067434


Number of distinct prime factors in binomial(2*n,n).


17



1, 2, 2, 3, 3, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 10, 10, 9, 10, 10, 10, 10, 12, 13, 12, 12, 13, 14, 14, 14, 14, 14, 15, 14, 15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 18, 18, 19, 20, 19, 19, 19, 20, 20, 21, 21, 21, 21, 22, 22, 23, 24, 23, 23, 23, 23, 24, 24, 24, 25, 25
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS



LINKS



FORMULA



MAPLE

a := n > nops(numtheory:factorset(binomial(2*n, n))):


MATHEMATICA

Table[Length[FactorInteger[Binomial[2 n, n]]], {n, 100}] (* T. D. Noe, Aug 17 2011 *)


PROG

(Haskell)
(PARI) valp(n, p)=my(s); while(n\=p, s+=n); s


CROSSREFS



KEYWORD

easy,nonn


AUTHOR



STATUS

approved



