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 A033471 #20 Jul 08 2025 19:52:46 %S A033471 1,18,810,10206,65610,1299078,483611310,9565938,7317942570, %T A033471 103053850074,383546284110,1443528742014,257010878197710, %U A033471 5083731656658,6634269811938690,982924264619854326,315013432104812970 %N A033471 Denominator of Bernoulli(2n,1/3). %H A033471 <a href="/index/Be#Bernoulli">Index entries for sequences related to Bernoulli numbers.</a> %p A033471 with(numtheory): seq(denom(bernoulli(2*n, 1/3)), n=0..20); %t A033471 Denominator/@BernoulliB[2Range[0,20],1/3] (* _Harvey P. Dale_, May 11 2011 *) %o A033471 (PARI) a(n) = denominator(subst(bernpol(2*n), x, 1/3)); \\ _Michel Marcus_, Sep 16 2020 %Y A033471 Cf. A033470 (numerators). %K A033471 nonn,frac %O A033471 0,2 %A A033471 _N. J. A. Sloane_