a(1)=1. a(2)=2 because a(2)+a(1)=2+1=3 which is a multiple of 1. Could not use a(2)=1 since 1 has already been used. a(3)=4 so that a(3)+a(2)=4+2=6 which is a multiple of 2, etc.

CROSSREFS

Cf. A099506 for similar sequence with a(n)+a(n-1)=multiple of n.