A336806 a(n) = prime(k) for the first k such that Product_{j=k..k+n-1} prime(j) mod Sum_{j=k..k+n-1} prime(j) is prime.

3, 5, 3, 13, 3, 23, 5, 67, 5, 37, 3, 41, 5, 29, 19, 23, 37, 19, 7, 17, 5, 7, 3, 7, 19, 31, 5, 13, 3, 23, 19, 5, 23, 83, 13, 17, 53, 5, 7, 17, 11, 23, 41, 7, 97, 17, 47, 37, 61, 43, 89, 5, 13, 7, 113, 41, 5, 5, 7, 5, 29, 11, 5, 17, 61, 43, 79, 29, 31, 31, 11, 97, 73, 23, 53, 97, 13, 89, 11, 103

Offset

2,1

Links

Robert Israel, Table of n, a(n) for n = 2..7700

Example

a(4) = 3 as 3*5*7*11 mod (3+5+7+11) = 11 is prime.

Maple

f:= proc(n) local L, k;
  L:= [seq(ithprime(k), k=1..n)];
  do
    if isprime(convert(L, `*`) mod convert(L, `+`)) then return L[1] fi;
    L:= [op(L[2..-1]), nextprime(L[-1])];
  od;
end proc:
map(f, [$2..100]);

Crossrefs

Sequence in context: A059887 A023585 A089948 * A023583 A266603 A121278

Adjacent sequences: A336803 A336804 A336805 * A336807 A336808 A336809

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Jan 27 2021

Status

approved