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 A096048 #9 Nov 13 2012 11:29:22 %S A096048 1,42,1446,51486,1848966,66524910,2394568086,86201542014, %T A096048 3103229527206,111716029897998,4021774981740726,144783880503964062, %U A096048 5212219528644719046,187639901505929327406,6755036440486736068566 %N A096048 a(n)=B(2n,6)/B(2n) (see comment). %C A096048 B(n,p)=sum(i=0,n,p^i*sum(j=0,i,binomial(n,j)*B(j))) where B(k)=k-th Bernoulli number %F A096048 a(n)=(1/10)*(11*36^n+2*9^n+3*4^n-6); a(0)=1, a(1)=42, a(2)=1446, a(3)=51486 and a(n)=50*a(n-1)-553*a(n-2)+1800*a(n-3)-1296*a(n-4) %o A096048 (PARI) a(n)=sum(i=0,2*n,6^i*sum(j=0,i,binomial(2*n,j)*bernfrac(j)))/bernfrac(2*n) %o A096048 (Maxima) a[0]:1$ a[1]:42$ a[2]:1446$ a[3]:51486$ a[n]:=(1/10)*(11*36^n+2*9^n+3*4^n-6)$ A096048(n):=a[n]$ makelist(A096048(n),n,0,30); /* _Martin Ettl_, Nov 13 2012 */ %Y A096048 Cf. A096045, A096046, A096047. %K A096048 nonn %O A096048 0,2 %A A096048 _Benoit Cloitre_, Jun 17 2004