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

1,4

Links

Table of n, a(n) for n=1..73.

Formula

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

Example

a(3) = 11 mod 5 = 1.

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 *)

Prog

(PARI) first(m)=vector(m, i, prime(i+2)% prime(i)); \\ Anders Hellström, Aug 20 2015
(Magma) [NthPrime(n+2) mod NthPrime(n): n in [1..80]]; // Vincenzo Librandi, Aug 20 2015

Crossrefs

Cf. A031131.

Sequence in context: A318355 A318237 A201572 * A001734 A342373 A173067

Adjacent sequences: A261465 A261466 A261467 * A261469 A261470 A261471

Keyword

nonn,easy

Author

Altug Alkan, Aug 20 2015

Status

approved