Hello SeqFans,
what is the last term of S?
S = 2,1,4,6,40,20,46,8,4,24,60,...
a(n) = smallest positive integer not already in S such
that the partial sum P of S' digits d(1)+...+d(k) is prime.
Example (read P terms vertically):
S = 2,1,4,6,40,20,46,8,4,24,60,...
P = 2 3 7 1 11 11 22 3 4 44 55
3 77 99 39 7 1 37 33
Best,
É.