%I #17 Mar 01 2024 07:25:25
%S 1,1,3,7,17,41,100,240,580,1400,3380,8160,19700,47560,114820,277200,
%T 669220,1615640,3900500,9416640,22733780,54884200,132502180,319888560,
%U 772279300,1864447160,4501173620,10866794400,26234762420,63336319240
%N Overlay of Pell companion numbers: a(n) = A001333(n) + A001333(n-6).
%H Paolo Xausa, <a href="/A131721/b131721.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,1).
%F a(n) = A001333(n), n<6. a(n) = A001333(n)+A001333(n-6) = 20*A000129(n-3), n>=6.
%F O.g.f.: (x-1)(x^2+1)(x^4-x^2+1)/(-1+2x+x^2). - _R. J. Mathar_, Jul 16 2008
%F For n>5, a(n) = 100*A000129(n+1) -240*A000129(n). - _R. J. Mathar_, Feb 05 2024
%t LinearRecurrence[{2, 1}, {1, 1, 3, 7, 17, 41, 100, 240}, 50] (* _Paolo Xausa_, Mar 01 2024 *)
%Y Cf. A131710.
%K nonn,easy
%O 0,3
%A _Paul Curtz_, Sep 15 2007
%E Edited and extended by _R. J. Mathar_, Jul 16 2008