A316497 a(n) = gcd(A081939(n), A081939(n+1)).

2, 2, 2, 2, 11, 11, 11, 11, 11, 11, 11, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 13, 5, 7, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 22, 22, 22, 22, 22, 22, 22, 22, 22, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 22, 22, 22, 22, 22, 22, 22, 22, 22, 11, 55

Offset: 1

Author

Robert Israel, Jul 04 2018

Keywords

• nonn
• base

Examples

			A081939(3)=6 and A081939(4)=8, so a(3)=gcd(6,8)=2.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to palindromes

Crossrefs

Cf. A081939.

Programs

Maple

# with list R containing terms of A081939
seq(igcd(R[i],R[i+1]),i=1..nops(R)-1)