A192327 a(n) = prime(n) mod 2*n.

0, 3, 5, 7, 1, 1, 3, 3, 5, 9, 9, 13, 15, 15, 17, 21, 25, 25, 29, 31, 31, 35, 37, 41, 47, 49, 49, 51, 51, 53, 3, 3, 5, 3, 9, 7, 9, 11, 11, 13, 15, 13, 19, 17, 17, 15, 23, 31, 31, 29, 29, 31, 29, 35, 37, 39, 41, 39, 41, 41, 39, 45, 55, 55, 53, 53, 63, 65, 71, 69, 69, 71, 75, 77, 79, 79

Offset: 1

Author

Pasi Airikka, Jun 28 2011

Keywords

• nonn
• easy

Examples

			a(1) = prime(1) mod even(1) = 2 mod 2 = 0.
a(5) = prime(5) mod even(5) = 11 mod 10 = 1.
		

Links

• Michel Marcus, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A004648.

Programs

MATLAB

% n = number of computed terms of sequence
for i=1:n,
    a(i) = mod(prime(i),even(i)) ;
end

Magma

A192327:=func< n | NthPrime(n) mod 2*n >; [ A192327(n): n in [1..80] ]; // Klaus Brockhaus, Jul 10 2011

Maple

A192327 := proc(n) modp(ithprime(n),2*n) ; end proc:
seq(A192327(n),n=1..80) ; # R. J. Mathar, Jul 11 2011

Mathematica

Table[Mod[Prime[n], 2n], {n, 50}] (* Alonso del Arte, Jun 29 2011 *)

PARI

a(n)=prime(n)%(2*n) \\ Charles R Greathouse IV, Jun 29 2011

Formula

a(n) = A000040(n) mod (2*n).