Hey guys,
I've been thinking for a formula but i wasn't able to figure out. Maybe someone smarter could give me a hand.<p>The series:
b, e, g, i, k, n, p, y, 10, 12, 14, 16, 18, 1a, 1c, 1e, 1g, 1i, 1u, 1w, 1z, 21, 23, 2b, 2e, 2g, 2i, 2k, 2m, 2o, 2r, 2t, 2v, 2x, 30, 34, 37, 39, 3c, 3e, 3g, 3i, 3m , 3o, 3q, 3s, 3v , 3y, 40, 42, 44 , 46, 48, 4a, 4d, 4g, 4n, 51, 5n, 5p, 5s, 5u, 5x, 60, 62, 64, 66, 68, 6b, 6j, 6n, 6p, 6r, 6t, 6w, 71, ...<p>Thanks for your help!