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 A106051 #13 Mar 03 2023 17:54:14 %S A106051 1,1,2,2,4,4,16,4,8,8,12,8,16,4,128,4,32,8,64,2,48,8,64,8,16,16,128, %T A106051 32,128,4,192,32,64,32,64,8,512,32,32,4,96,16,64,16,64,8,64,16,2048, %U A106051 32,64,8,32,32,512,32,1024,64,32,16,96,16,512,256,2048,8,32 %N A106051 Number of divisors of the Euler number E(2n) (A000364). %C A106051 Notice that all listed terms are powers of 2 except for the 10th, 20th and 30th. It would be interesting to know whether this pattern continues. Note: Various sources give differing values for the Euler numbers. A000364 gives {1,1,5,61,1385,50521,2702765,199360981,19391512145,...}, whereas Mathematica gives {1,0,-1,0,5,0,-61,0,1385,0,-50521,...}. %H A106051 Sean A. Irvine, <a href="/A106051/b106051.txt">Table of n, a(n) for n = 0..86</a> %F A106051 a(n) = A000005(A000364(n)). %e A106051 E(4) = 1385 has divisors {1,5,277,1385}, so a(4) = 4. %p A106051 a:= n-> numtheory[tau](abs(euler(2*n))): %p A106051 seq(a(n), n=0..30); # _Alois P. Heinz_, Mar 03 2023 %t A106051 a ={};For[n=0, n<=33, n++, {Eu=EulerE[2*n];L=Length[Divisors[Eu]];a=Append[a, L]}];a %Y A106051 Cf. A000005, A000364. %K A106051 nonn %O A106051 0,3 %A A106051 _John W. Layman_, May 06 2005 %E A106051 a(34)-a(49) from _Robert G. Wilson v_, May 09 2005 %E A106051 a(46) corrected and more terms from _Sean A. Irvine_, Mar 03 2023