A152270 Let f(n)=Floor[Mod[10^k*(7/(4*k + 1) - 6/(4*k + 3) - 1/(4*k + 5)), 3]]; M0 = {{0, 1}, {1, 1/2}}; M = {{0, 2}, {2, 1}}; as Mh=M0.M.(M0+I*f[n]); v[(n)=Mh.v(n-1), then a(n) is the first element of v.

0, 1, -3, -13, 15, -37, 23, -125, -467, -2269, -2269, -12147, -66877, -66877, -66877, -66877, -370963, -2061725, -11464371, 17899313, 99555423, 99555423, -155471765, -864636987, 1350136841, 1350136841, -2108411107, -2108411107

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Mathematica

f[k_] = Floor[Mod[10^k*(7/(4*k + 1) - 6/(4*k + 3) - 1/(4*k + 5)), 3]];
M0 = {{0, 1}, {1, 1/2}}; M = {{0, 2}, {2, 1}};
Mh[n_] := M0.(M.Inverse[f[n]*IdentityMatrix[2] + M0]);
v[0] = {0, 1};
v[n_] := v[n] = Mh[n].v[n - 1]
Table[ -v[n][[1]]/2, {n, 0, 30}]

Crossrefs

Sequence in context: A146512 A082704 A353060 * A032919 A340018 A216044

Adjacent sequences: A152267 A152268 A152269 * A152271 A152272 A152273

Keyword

sign,uned,obsc,base

Author

Roger L. Bagula and Alexander R. Povolotsky, Dec 01 2008

Status

approved