A340781 a(n) = (n - 1)*prime(n + 1) mod prime(n).

0, 2, 4, 5, 8, 7, 12, 9, 2, 18, 29, 7, 24, 9, 37, 37, 32, 41, 5, 38, 47, 5, 49, 6, 96, 50, 1, 54, 3, 67, 120, 55, 64, 52, 68, 59, 59, 148, 61, 61, 80, 48, 84, 172, 88, 142, 130, 188, 96, 196, 67, 102, 38, 67, 67, 67, 112, 71, 232, 118, 34, 268, 248, 126, 256, 276

Offset: 1

Author

Stefano Spezia, Jan 21 2021

Keywords

• nonn
• look

Links

• Stefano Spezia, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A033286, A306192, A340128, A340649.

Programs

Mathematica

Table[Mod[(n-1)Prime[n+1],Prime[n]],{n,66}]

PARI

a(n) = ((n-1)*prime(n+1)) % prime(n); \\ Michel Marcus, Jan 21 2021

Formula

a(n) = A306192(n) mod A000040(n).