1,2

Does every generation after the initial 1 contain a prime?

Ivan Neretin, Table of n, a(n) for n = 1..10000

Gevorg Hmayakyan, Trig identity for a(n)

Product_{j=0..n-1} cos(4^j) = 2^(-n+1)*Sum_{i=2^(n-1)..2^n-1} cos(a(i)). - Gevorg Hmayakyan, Jan 15 2017

Sum_{i=2^(n-1)..2^n-1} cos(a(i)/4^(n-1)*Pi/2) = 0. - Gevorg Hmayakyan, Jan 15 2017

0th generation: 1

1st generation: 3 5

2nd generation: 11 13 19 21

Sequence in context: A047621 A239636 A117205 * A166089 A136208 A045405

Adjacent sequences: A147989 A147990 A147991 * A147993 A147994 A147995

nonn

Clark Kimberling, Dec 07 2008

approved