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 A200678 #20 Jul 25 2021 02:24:53 %S A200678 1,2,3,4,6,8,10,12,16,20,24,28,36,44,52,60,76,92,108,124,156,188,220, %T A200678 252,316,380,444,508,636,764,892,1020,1276,1532,1788,2044,2556,3068, %U A200678 3580,4092,5116,6140,7164,8188,10236,12284,14332,16380,20476,24572,28668,32764 %N A200678 Partial sums of A200675. %C A200678 Partial sums of powers of 2 repeated 4 times. %C A200678 The first few terms of this sequence appear in the reference by Szymczak, et al., as contour levels in intensity maps of maser emissions. %H A200678 M. Szymczak, R. J. Cohen and A. M. S. Richards, <a href="http://adsabs.harvard.edu/full/1998MNRAS.297.1151S">Full polarization structure of the OH main-line maser envelopes of W Hydrae</a>, Monthly Notices of the Royal Astronomical Society, Volume 297, Issue 4, pp. 1151-1162. %H A200678 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,2,-2). %F A200678 G.f.: x*(1+x)*(1+x^2) / ( (x-1)*(2*x^4-1) ). - _R. J. Mathar_, Nov 21 2011 %e A200678 a(5) = 1+1+1+1+2 = 6. %o A200678 (BASIC) for i=0 to 12 : for j=1 to 4 : s=s+2^i : print s : next j : next i %Y A200678 Cf. A027383, A200672, A200675. %K A200678 nonn %O A200678 1,2 %A A200678 _Jeremy Gardiner_, Nov 20 2011