Binomial transform of
A118239 (Engel expansion of cosh(1)).
Table of successive differences of a(n):
1, 3, 17, 73, 257, 801, 2305,...
2, 14, 56, 184, 544, 1504,...
12, 42, 128, 360, 960,...
30, 86, 232, 600,...
56, 146, 368,...
90, 222,...
132,...
etc.
Via b(n) = 0, 0, 0 followed by
A055580(n), i.e., 0, 0, 0, 1, 7, 31, 111, ... (the main sequence for the recurrence), a link can be found between a(n) and
A002064(n): c(n) = b(n+1) - 2*b(n) = 0, 0, 1, 5, 17, 49, 129, ... (the main sequence for the signature (5, -8, 4)).
