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 A247416 #14 Sep 17 2014 11:51:01
%S A247416 2,6,21,75,273,1008,3762,14158,53635,204270,781378,2999906,11553234,
%T A247416 44612760,172671925,669679793,2601913466,10125418060,39459828905,
%U A247416 153977743500,601545298200,2352559491900,9209476821105,36084150102001,141499349638556,555292275455022,2180689496523468,8569380062230708
%N A247416 Number of friezes of type B_n.
%H A247416 B. Fontaine and P.-G. Plamondon, <a href="http://arxiv.org/abs/1409.3698">Counting friezes in type D_n</a>, arXiv:1409.3698 [math.CO], 2014.
%F A247416 a(n) = sum_{m=1..floor(sqrt(n+1))} binomial(2n-m^2+1,n).
%o A247416 (PARI) a(n) = sum(m=1,sqrtint(n+1), binomial(2*n-m^2+1,n) ); \\ _Joerg Arndt_, Sep 16 2014
%Y A247416 Cf. A000108, A000984 and A247415, the number of friezes of type A_n, C_n and D_n.
%K A247416 nonn
%O A247416 1,1
%A A247416 _Bruce Fontaine_, Sep 16 2014