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

1,1

Links

Table of n, a(n) for n=1..18.

Prog

(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)))

Crossrefs

Cf. A018252, A124522, A360097.

Sequence in context: A098045 A293817 A360097 * A360528 A336004 A296795

Adjacent sequences: A360255 A360256 A360257 * A360259 A360260 A360261

Keyword

nonn,more

Author

Jean-Marc Rebert, Feb 01 2023

Status

approved