login
A067437
Number of distinct prime factors in binomial(2*n,n)+1.
1
1, 1, 2, 1, 2, 2, 1, 2, 3, 2, 2, 1, 2, 3, 3, 4, 2, 2, 1, 2, 4, 1, 3, 2, 4, 4, 3, 4, 3, 2, 3, 2, 2, 2, 5, 4, 3, 1, 4, 3, 2, 3, 2, 4, 2, 1, 3, 3, 4, 2, 6, 3, 7, 5, 4, 5, 3, 3, 2, 3, 5, 1, 5, 2, 3, 4, 3, 1, 6, 6, 3, 1, 3, 2, 5, 2, 4, 4, 4, 2, 6, 2, 2, 1, 3, 4, 3, 2, 4, 3
OFFSET
1,3
LINKS
FORMULA
a(n) = A001221(A244174(n)). - Amiram Eldar, Apr 23 2022
MATHEMATICA
a[n_] := PrimeNu[Binomial[2*n, n] + 1]; Array[a, 90] (* Amiram Eldar, Apr 23 2022 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Feb 23 2002
STATUS
approved