A104723 Moebius transform of Jacobsthal numbers.
0, 1, 0, 2, 4, 10, 18, 42, 80, 168, 330, 682, 1340, 2730, 5418, 10910, 21760, 43690, 87192, 174762, 349180, 699006, 1397418, 2796202, 5590960, 11184800, 22366890, 44739072, 89473020, 178956970, 357902670, 715827882, 1431633920, 2863310846
Offset: 0
Keywords
Formula
a(n) = Sum_{d|n} mu(n/d)*A001045(d).
a(n+3) = 3*A027375(n+3) (since the Moebius transform of (-1)^n is (-1, -1, 2, 0, 0, 0, ...)).
G.f.: Sum_{k>=1} mu(k) * x^k / (1 - x^k - 2*x^(2*k)). - Ilya Gutkovskiy, Feb 06 2020