This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A142718 #20 Aug 11 2025 23:12:30
%S A142718 1,1,11,17,29,199,321,521,3571,5777,9349,64079,103681,167761,1149851,
%T A142718 1860497,3010349,20633239,33385281,54018521,370248451,599074577,
%U A142718 969323029,6643838879,10749957121,17393796001,119218851371,192900153617,312119004989,2139295485799
%N A142718 Odd terms in A014217.
%H A142718 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,19,0,0,-19,0,0,1).
%F A142718 a(n) = 19*a(n-3) - 19*a(n-6) + a(n-9).
%t A142718 LinearRecurrence[{0,0,19,0,0,-19,0,0,1},{1,1,11,17,29,199,321,521,3571},30] (* _James C. McMahon_, Aug 11 2025 *)
%Y A142718 Cf. A014217.
%K A142718 easy,nonn
%O A142718 1,3
%A A142718 _Paul Curtz_, Sep 27 2008
%E A142718 Edited by _N. J. A. Sloane_, Sep 27 2008
%E A142718 a(19)-a(30) from _James C. McMahon_, Aug 11 2025