A360258 a(n) is the smallest k such that A360097(k) = n.

13, 14, 20, 7, 5, 10, 4, 9, 63, 6, 42, 1590, 1, 2, 5172911835, 974749335, 21, 26135070

Offset: 1

Author

Jean-Marc Rebert, Feb 01 2023

Keywords

• nonn
• more

Crossrefs

Cf. A018252, A124522, A360097.

Programs

PARI

a360097(n)=my(k=1);while(isprime(2*n*k-1)||isprime(2*n*k+1),k++);k
a(n)=for(i=1,+oo,my(k=a360097(i));if(k==n,return(i)))