1,1

The next term is > 25000.

Equals A063791 + 1 - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008

User group for PFGW & PrimeForm programs.

a(1)=4 because 2^4-4-1=11 is prime.

Cf. A000295 2^n-n-1 (column 2 of the Eulerian numbers), A099440 primes in A000295, A099441 2^n-n-1 is a semiprime, A099442 semiprimes in A000295.

Adjacent sequences: A099436 A099437 A099438 this_sequence A099440 A099441 A099442

Sequence in context: A114719 A116954 A102686 this_sequence A001581 A114335 A099355

hard,nonn

Hugo Pfoertner (hugo(AT)pfoertner.org), Oct 18 2004