OFFSET
1,2
EXAMPLE
Fifth row is 1, 5, 9, 13, 17, so a(5) = 45.
PROG
(Magma) S:=[ [1] ]; for n in [2..21] do Append(~S, [1+i*Max([ x: x in S[n-1] | x eq 1 or not IsPrime(x) ]): i in [0..n-1] ]); end for; [ &+R: R in S ];
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, May 31 2009
STATUS
approved