A340646 a(n) = (prime(n)^n) mod prime(n+1).

2, 4, 6, 3, 7, 16, 5, 9, 7, 1, 6, 16, 21, 32, 36, 16, 17, 22, 63, 4, 10, 75, 63, 96, 1, 38, 2, 66, 109, 100, 82, 119, 57, 53, 119, 67, 141, 137, 116, 89, 103, 85, 187, 101, 74, 58, 146, 144, 216, 37, 238, 16, 4, 21, 254, 185, 216, 187, 43, 15, 123, 109, 69

Offset

1,1

Links

Table of n, a(n) for n=1..63.

Example

a(1) = prime(1)^1 mod prime(1+1) = 2^1 mod 3 = 2 mod 3 = 2,
a(2) = prime(2)^2 mod prime(2+1) = 3^2 mod 5 = 9 mod 5 = 4,
a(3) = prime(3)^3 mod prime(3+1) = 5^3 mod 7 = 125 mod 7 = 6,
a(4) = prime(4)^4 mod prime(4+1) = 7^4 mod 11 = 2401 mod 11 = 3,
a(5) = prime(5)^5 mod prime(5+1) = 11^5 mod 13 = 161051 mod 13 = 7.

Prog

(Ruby) require 'prime'
values = []
primes = Prime.first(20)
primes.each_index do |n|
    next if n < 1
    values << (primes[n-1] ** n) % primes[n]
end
p values
(PARI) a(n)=my(p=prime(n)); lift(Mod(p, nextprime(p+1))^n); \\ Michel Marcus, Jan 14 2021

Crossrefs

Cf. A000040, A240546.

Sequence in context: A278376 A358209 A057336 * A236675 A210771 A359535

Adjacent sequences: A340643 A340644 A340645 * A340647 A340648 A340649

Keyword

nonn

Author

Simon Strandgaard, Jan 14 2021

Status

approved