A261468 a(n) = prime(n+2) mod prime(n).

1, 1, 1, 6, 6, 6, 6, 10, 8, 8, 10, 6, 6, 10, 12, 8, 8, 10, 6, 8, 10, 10, 14, 12, 6, 6, 6, 6, 18, 18, 10, 8, 12, 12, 8, 12, 10, 10, 12, 8, 12, 12, 6, 6, 14, 24, 16, 6, 6, 10, 8, 12, 16, 12, 12, 8, 8, 10, 6, 12, 24, 18, 6, 6, 18, 20, 16, 12, 6, 10, 14, 14, 12

Offset: 1

Author

Altug Alkan, Aug 20 2015

Keywords

• nonn
• easy

Examples

			a(3) = 11 mod 5 = 1.
		

Crossrefs

Cf. A031131.

Programs

Magma

[NthPrime(n+2) mod NthPrime(n): n in [1..80]]; // Vincenzo Librandi, Aug 20 2015

Mathematica

a[n_]:=PowerMod[Prime[n + 2], 1, Prime[n]]; Table[a[n], {n, 80}] (* Vincenzo Librandi, Aug 20 2015 *)
Mod[#[[3]],#[[1]]]&/@Partition[Prime[Range[80]],3,1] (* Harvey P. Dale, Mar 14 2020 *)

PARI

first(m)=vector(m,i,prime(i+2)% prime(i)); \\ Anders Hellström, Aug 20 2015

Formula

a(n) = A031131(n) = A075527(n) for n>3. - Alois P. Heinz, Aug 20 2015