CGF := proc(n, k) option remember; local G; G := add(2^binomial(q,2)*z^q/q!, q=0..n); n!*coeftayl(log(G)^k/k!, z=0, n); end; C := proc(n, k) option remember; if k = 0 and n = 0 then return 1 fi; if k = 0 or n = 0 then return 0 fi; add(binomial(n-1,q)*C(q,k-1)*2^binomial(n-q,2), q=0..n-1) - add(binomial(n-1,q)*C(q+1,k)*2^binomial(n-1-q,2), q=0..n-2); end; OEIS := mx -> seq(seq(C(n,k), k=1..n), n=1..mx); BFILE := proc(mx) local fname, fd, n, k, idx; fname := sprintf("conn-k-compB-%a.txt", mx); fd := fopen(fname, WRITE); idx := 1; for n to mx do for k to n do fprintf(fd, "%a %a\n", idx, C(n, k)); idx := idx + 1; od; od; fclose(fd); return idx; end;