%I #21 Jul 02 2023 16:08:59
%S 11,54,161,396,887,1890,3917,7992,16163,32526,65273,130788,261839,
%T 523962,1048229,2096784,4193915,8388198,16776785,33553980,67108391,
%U 134217234,268434941,536870376,1073741267,2147483070,4294966697,8589933972,17179868543,34359737706
%N A hierarchical sequence (S(W2{3}c) - see A059126).
%H Jonas Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4, -5, 2).
%F Conjectures from _Colin Barker_, Oct 07 2015: (Start)
%F a(n) = -53 + 2^(6+n) - 21*n.
%F a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) for n > 2.
%F G.f.: -(10*x+11) / ((x-1)^2*(2*x-1)).
%F (End)
%F a(n) = a(n-1) + Sum_{k=0..7*2^n-1} A059127(7*2^n-7+k) with a(-1)=0. - _Sean A. Irvine_, Sep 12 2022
%Y Cf. A059126, A059127.
%K nonn
%O 0,1
%A _Jonas Wallgren_, Jan 19 2001
%E More terms from _Sean A. Irvine_, Sep 12 2022