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 A061801 #23 Aug 25 2022 09:17:13
%S A061801 1,8,50,302,1814,10886,65318,391910,2351462,14108774,84652646,
%T A061801 507915878,3047495270,18284971622,109709829734,658258978406,
%U A061801 3949553870438,23697323222630,142183939335782,853103636014694
%N A061801 a(n) = (7*6^n - 2)/5.
%C A061801 Sum of n-th row of triangle of powers of 6: 1; 1 6 1; 1 6 36 6 1; 1 6 36 216 36 6 1; ....
%H A061801 Harry J. Smith, <a href="/A061801/b061801.txt">Table of n, a(n) for n=0,...,200</a>
%F A061801 G.f.: (1+x)/(1-6*x)/(1-x) [_Zerinvary Lajos_, Jan 11 2009]
%F A061801 a(n) = 6*a(n-1) + 2, a(0) = 1. - _Philippe Deléham_, Feb 23 2014
%F A061801 a(n) = Sum_{k=0..n} A112468(n,k)*7^k. - _Philippe Deléham_, Feb 23 2014
%e A061801 a(2) = 50 = 1 + 6 + 36 + 6 + 1.
%e A061801 G.f. = 1 + 8*x + 50*x^2 + 302*x^3 + 1814*x^4 + 10886*x^5 + 65318*x^6 + ...
%p A061801 restart:g:=(1+x)/(1-6*x)/(1-x): gser:=series(g, x=0, 43): seq(coeff(gser, x, n), n=0..30); # _Zerinvary Lajos_, Jan 11 2009
%o A061801 (PARI) { for (n=0, 200, write("b061801.txt", n, " ", (7*6^n - 2)/5) ) } \\ _Harry J. Smith_, Jul 28 2009
%Y A061801 Cf. A057651, A112468, A112739.
%K A061801 nonn,easy
%O A061801 0,2
%A A061801 _Amarnath Murthy_, May 28 2001
%E A061801 More terms from Larry Reeves (larryr(AT)acm.org) and _Jason Earls_, May 28 2001.
%E A061801 Better description from _Dean Hickerson_, Jun 06 2001
%E A061801 Divided g.f. by x to match the offset. - _Philippe Deléham_, Feb 23 2014