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 A068944 #1 May 16 2003 03:00:00 %S A068944 0,0,0,2,7,28,108,414,1585,6087,23446,90532,350343,1358437,5276545, %T A068944 20527950,79976007,311984922,1218474389,4763911699,18643889114, %U A068944 73029856058,286302435505,1123267533520,4410123312095,17326303720537 %N A068944 Highest power of 9 dividing A068943(n) for n>0. %C A068944 Sequence was suggested by the discovery that the digital root of A068943 is 9 for all n>3. %e A068944 a(11)=23446 since f(11,11,11)=9^binomial(12,10) * 6^binomial(15,10) * 3^(18,10) * other terms. this implies a(11)=binomial(12,10) + 1/2*(binomial(15,10)-1 + binomial(18,10)). %Y A068944 Cf. A068943, A068945. %K A068944 nonn %O A068944 1,4 %A A068944 Francois Jooste (phukraut(AT)hotmail.com), Mar 09 2002