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 A068905 #13 Apr 23 2017 01:00:30 %S A068905 1,3,4,7,6,66,8,15,13,153,12,378,14,276,276,31,18,741,20,861,496,630, %T A068905 24,1770,31,861,40,1540,30,59640,32,63,1128,1431,1128,4095,38,1770, %U A068905 1540,4005,42,142880,44,3486,3003,2556,48,7626 %N A068905 Binomial(sigma(n),omega(n)), where sigma(n) is the sum of divisors of n (A000203) and omega the number of distinct prime factors (A001221). %H A068905 G. C. Greubel, <a href="/A068905/b068905.txt">Table of n, a(n) for n = 1..1000</a> %t A068905 Binomial[DivisorSigma[1,#],Length[FactorInteger[#]]]&/@Range[50] (* _Harvey P. Dale_, Feb 18 2011 *) %o A068905 (PARI) a(n)=binomial(sigma(n),omega(n)) \\ _Charles R Greathouse IV_, Feb 19 2013 %Y A068905 Cf. A068903, A068904. %K A068905 nonn %O A068905 1,2 %A A068905 _Reinhard Zumkeller_, Mar 06 2002