1,1

a(n) is the first prime p occurring at position m in A254077, satisfying the condition that A254077(m + 2i) = p*(i+2) for all i from 1 through n. Also, A254077(m-2) = p*2.

John P. Linderman calculated and confirmed a(6).

Table of n, a(n) for n=1..6.

John P. Linderman, Notes on computation of first 5 billion terms

John Mason, Some observations related to A254077

a(1)=5 because A254077(10)=5 and A254077(12)=15;

a(2)=17 because A254077(33)=17 and A254077(35)=51 and A254077(37)=68.

Cf. A254077.

Sequence in context: A102264 A122035 A052350 * A239195 A111746 A088645

Adjacent sequences: A318823 A318824 A318825 * A318827 A318828 A318829

nonn,more

John Mason, Sep 05 2018

approved