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 A133092 #24 Mar 07 2022 02:06:31 %S A133092 1,4,6,16,15,36,28,64,45,100,66,144,91,196,120,256,153,324,190,400, %T A133092 231,484,276,576,325,676,378,784,435,900,496,1024,561,1156,630,1296, %U A133092 703,1444,780,1600,861,1764,946,1936,1035,2116,1128,2304,1225,2500,1326,2704 %N A133092 Row sums of triangle A133091. %C A133092 Even squares interleaved with hexagonal numbers, A000384, such that A000384(n), (n,odd) = A000384((n+1)/2). %H A133092 Bruno Berselli, <a href="/A133092/b133092.txt">Table of n, a(n) for n = 1..1000</a> %H A133092 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,1). %F A133092 G.f.: x*(1 + 4*x + 3*x^2 + 4*x^3)/(1-x^2)^3. - _Philippe Deléham_, Mar 02 2012 %F A133092 a(n) = (n/4)*(3*n + (n-1)*(-1)^n + 1). - _Bruno Berselli_, Mar 02 2012 %F A133092 E.g.f.: (x/4)*(x*exp(-x) + (4 + 3*x)*exp(x)). - _G. C. Greubel_, Oct 21 2017 %F A133092 a(n) = 3*a(n-2) - 3*a(n-4) + a(n-6). - _Wesley Ivan Hurt_, Jun 08 2021 %e A133092 a(4) = 16 = sum of row 4 terms of triangle A133091: (2 + 4 + 6 + 4). %e A133092 a(4) = 16 = 4^2. %e A133092 a(7) = 28 = A000384(4), where A000384 = (1, 6, 15, 28, 45, 66, 91, ...). %t A133092 Table[(n/4)*(3*n + (n - 1)*(-1)^n + 1), {n, 48}] (* _Bruno Berselli_, Mar 02 2012 *) %o A133092 (PARI) for(n=1,50, print1((n/4)*(3*n+(n-1)*(-1)^n+1), ", ")) \\ _G. C. Greubel_, Oct 21 2017 %o A133092 (Magma) [(n/4)*(3*n+(n-1)*(-1)^n+1): n in [1..50]]; // _G. C. Greubel_, Oct 21 2017 %Y A133092 Cf. A133091, A000384. %K A133092 nonn,easy %O A133092 1,2 %A A133092 _Gary W. Adamson_, Sep 09 2007 %E A133092 Corrected and extended by _Philippe Deléham_, Mar 02 2012