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 A083426 #10 Apr 26 2023 10:00:53
%S A083426 1,6,40,276,1924,13452,94132,658860,4611892,32282988,225980404,
%T A083426 1581861804,11073030580,77511209964,542578461556,3798049214508,
%U A083426 26586344468788,186104411215980,1302730878380788,9119116148403372
%N A083426 a(n) = (4*7^n+2^n)/5.
%C A083426 Binomial transform of A083066.
%H A083426 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9,-14)
%F A083426 G.f.: (1-3*x)/((1-2*x)*(1-7*x)).
%F A083426 E.g.f.: (4*exp(7*x)+exp(2*x))/5.
%t A083426 LinearRecurrence[{9,-14},{1,6},20] (* _Harvey P. Dale_, Oct 13 2015 *)
%Y A083426 Cf. A083066.
%K A083426 easy,nonn
%O A083426 0,2
%A A083426 _Paul Barry_, Apr 30 2003