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 A081150 #13 Jan 11 2024 06:33:06 %S A081150 0,0,1,1,3,6,18,37,95,212,528,1226,2936,6822,16212,38081,90717,215414, %T A081150 516358 %N A081150 Number of even cycles in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506. %C A081150 For the convenience of the range notation above, we define A014137(-1) and A014138(-1) as zero. %H A081150 Antti Karttunen, <a href="/A089408/a089408.c.txt">Counted with the help of this C program</a>. %F A081150 a(n) = A081157(n) + A081160(n) + A081162(n) = A057507(n) - A081148(n). %Y A081150 Bisections: A081151, A081152. %Y A081150 Cf. A081157, A081160, A081162, A057507, A081148. %Y A081150 Cf. A014137, A014138, A057505, A057506. %K A081150 nonn,more %O A081150 0,5 %A A081150 _Wouter Meeussen_ and _Antti Karttunen_, Mar 10 2003