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 A340495 #22 Jan 11 2021 00:20:37 %S A340495 2,3,8,33,138,563,2268,9093,36398,145623,582528,2330153,9320658, %T A340495 37282683,149130788,596523213,2386092918,9544371743,38177487048, %U A340495 152709948273,610839793178,2443359172803 %N A340495 Records in first differences of A340494. %H A340495 Rémy Sigrist, <a href="/A340495/a340495.txt">C program for A340495</a> %F A340495 The sequence a(n)-4*a(n-1) appears to be -5, -4, 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, ... which is essentially 5*k+1 (k >= -1). The sequence itself appears to have g.f. = %F A340495 x*(2*x-1)*(2*x^2+5*x-2)/((1-x)^2*(1-4*x)). %o A340495 (C) See Links section. %Y A340495 Cf. A340488, A340494. %K A340495 nonn,more %O A340495 1,1 %A A340495 _Rémy Sigrist_ and _N. J. A. Sloane_, Jan 10 2021