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%I #44 Jan 19 2019 02:41:02
%S 1,5,37,293,2341,18725,149797,1198373,9586981,76695845,613566757,
%T 4908534053,39268272421,314146179365,2513169434917,20105355479333,
%U 160842843834661,1286742750677285,10293942005418277,82351536043346213
%N Number of cubic residues mod 8^n.
%H Ralf Stephan, <a href="https://arxiv.org/abs/math/0409509">Prove or disprove: 100 conjectures from the OEIS</a>, arXiv:math/0409509 [math.CO], 2004.
%H E. Wilmer and O. Schirokauer, <a href="http://www.oberlin.edu/math/faculty/wilmer/OEISconj25.pdf">A note on Stephan's conjecture 25</a>, 2004. [broken link]
%H E. Wilmer and O. Schirokauer, <a href="/A046636/a046636.pdf">A note on Stephan's conjecture 25</a>, 2004. [cached copy]
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9,-8).
%F a(n) = (4*8^n + 3)/7.
%F a(n) = 8*a(n-1) - 3 (with a(0)=1). - _Vincenzo Librandi_, Nov 18 2010
%F From _R. J. Mathar_, Feb 28 2011: (Start)
%F a(n) = A046530(8^n) = A046630(3n).
%F G.f.: ( 1-4*x ) / ( (1-8*x)*(1-x) ). (End)
%F a(n+1) = A226308(3n+2). - _Philippe Deléham_, Feb 24 2014
%t LinearRecurrence[{9, -8}, {1, 5}, 20] (* _Jean-François Alcover_, Jan 19 2019 *)
%Y Cf. A007583.
%K nonn
%O 0,2
%A _David W. Wilson_
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