1,1

Another term is a(16)=6766. All values in the sequence are Fermat and Lucas PRPs except for the first which was proved with ECM. The larger values won't be easily provable until RSA-2048 is factored, which has a prize of $200000 for its factorization.

RSA-2048 is A391940(54). Note that all the remaining prizes were retracted when the RSA challenge officially ended in 2007. - Antti Karttunen, Jan 01 2026

Wikipedia, RSA-2048

Cf. A391940.

Cf. also A108573, A108375, A113932.

Sequence in context: A075299 A031712 A251049 * A186547 A237741 A335613

Adjacent sequences: A108878 A108879 A108880 * A108882 A108883 A108884

more,nonn

Jason Earls, Jul 14 2005

approved