A254380 2^2*3^3*...*a(n)^a(n) + 1 is prime, a(n) is prime, a(n)>a(n-1), and a(n) is minimal.
2, 3, 19, 11251
Offset: 1
Examples
a(1)=2 because 2 and (2^2)+1=5 are prime. a(2)=3 because 3 and (2^2*3^3)+1=109 are prime. a(3)=19 because 19 and (2^2*3^3*19^19)+1=213669322811313867625389733 are prime, and this did not work for either 5, 7, 11, 13.
Links
- Chris K. Caldwell and G. L. Honaker, Jr. Prime Curios!
Extensions
a(4) found by Chris K. Caldwell
Comments