-2642

Appears in sequences

• Imaginary part of (1+2i)^n.at n=11A006496
• Square array A(n,k), n >= 1, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. log(1 + Sum_{j>=1} j^k * x^j/j!).at n=39A308484