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 A097953 #14 Jun 11 2022 03:32:44
%S A097953 1,0,1,1,1,15,11,201,561,4575,25171,187801,1400521,11694735,103903931,
%T A097953 993285801,10113814881,109470594495,1254389104291,15173016742201,
%U A097953 193187969483641,2582736821247855,36172850924874251
%N A097953 Boustrophedon transform of ((-2)^n+0^n)/2.
%C A097953 Inverse binomial transform of A062272.
%F A097953 E.g.f.: (1+exp(-2x))(sec(x)+tan(x))/2.
%F A097953 a(n) ~ n! * (1+exp(-Pi)) * (2/Pi)^(n+1). - _Vaclav Kotesovec_, Sep 29 2013
%t A097953 CoefficientList[Series[(1+1/E^(2*x))*(1+Sin[x])/Cos[x]/2, {x, 0, 20}], x]* Range[0, 20]! (* _Vaclav Kotesovec_, Sep 29 2013 *)
%o A097953 (Python)
%o A097953 from itertools import islice, accumulate
%o A097953 def A097953_gen(): # generator of terms
%o A097953 blist, m = tuple(), 1
%o A097953 while True:
%o A097953 yield (blist := tuple(accumulate(reversed(blist),initial=(m+1)//2)))[-1]
%o A097953 m *= -2
%o A097953 A097953_list = list(islice(A097953_gen(),20)) # _Chai Wah Wu_, Jun 11 2022
%Y A097953 Cf. A000734, A062272.
%K A097953 nonn
%O A097953 0,6
%A A097953 _Paul Barry_, Jan 21 2005