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 A145909 #14 Mar 08 2022 03:10:11 %S A145909 0,8,8,16,80,40,56,224,32,40,440,176,208,728,280,320,1088,136,152, %T A145909 1520,560,616,2024,736,800,2600,312,336,3248,1160,1240,3968,1408,1496, %U A145909 4760,560,592,5624,1976,2080,6560,2296,2408,7568,880,920 %N A145909 First 6-fold decimation of A061039. First bisection of A144454. %H A145909 G. C. Greubel, <a href="/A145909/b145909.txt">Table of n, a(n) for n = 0..5000</a> %F A145909 a(n) = A061039(6*n+3). %p A145909 A145909 := proc(n) ; A061039(6*n+3) end proc: %p A145909 seq(A145909(n),n=0..80) ; # _R. J. Mathar_, Jan 06 2011 %t A145909 Numerator[(1/9)*(1 - 1/(2*Range[0,75]+1)^2)] (* _G. C. Greubel_, Mar 08 2022 *) %o A145909 (Sage) [numerator((1/9)*(1 - 1/(2*n+1)^2)) for n in (0..75)] # _G. C. Greubel_, Mar 08 2022 %Y A145909 Cf. A061039, A144454. %K A145909 nonn,easy,less %O A145909 0,2 %A A145909 _Paul Curtz_, Oct 24 2008