Hi A246521 has offset 0, and first values 0, 1, 3, 7. So a(0)=0, a(1)=1, etc. In 2014 I myself submitted a b-file, which has, as its first few lines: 1 0 2 1 3 3 4 7 Did I get it wrong in 2014? Should I have submitted as follows? 0 0 1 1 2 3 3 7 Thanks john