2,1

Table of n, a(n) for n=2..100.

10 has prime factors 2 and 5, which become 3 and 6 when respectively increased by 1, and gcd(3, 6) = 3. Therefore, a(10) = 3.

Table[Apply[GCD, (Transpose[FactorInteger[n]][[1]] + 1)], {n, 2, 100}]

Sequence in context: A262150 A325594 A104076 * A332880 A281626 A327650

Adjacent sequences: A238158 A238159 A238160 * A238162 A238163 A238164

nonn,easy

Joseph L. Pe, Feb 18 2014

approved