A171525 Numerator of (n-th noncomposite/n).

1, 1, 1, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227

Offset: 1

Author

Jaroslav Krizek, Dec 11 2009

Keywords

• nonn
• easy

Comments

Numerator of (A008578(n)/n). a(1)= a(2) = a(3) = 1, a(n) = A008578(n) = A000040(n-1) for n >= 4.

Programs

PARI

a(n)=if(n>3,prime(n-1),1) \\ Charles R Greathouse IV, Aug 22 2011