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 A159953 #20 Dec 26 2024 03:55:45
%S A159953 2,2,3,2,2,3,3,2,2,3,5,2,3,3,4,2,2,2,2,4,2,2,2,2,2,5,2,2,6,4,2,2,5,2,
%T A159953 5,3,3,3,7,3,6,2,3,2,2,6,3,2,4,2,3,8,2,9,4,2,6,2,2,2,2,2,2,4,8,4,2,2,
%U A159953 2,3,4,3,9,2,10,2,3,2,4,4,3,4,2,2,11,5,2,5,2,3,4,2,2,3,5,3,8,7,4,15,2,4,7,8
%N A159953 Values in A054973 larger than 1.
%C A159953 This is a survey of how many solutions the equation sigma(x)=k has for k in A159886, or about the lengths of the plateaus in A007609.
%H A159953 Amiram Eldar, <a href="/A159953/b159953.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1095 from Jean-François Alcover)
%H A159953 Max Alekseyev, <a href="https://oeis.org/wiki/User:Max_Alekseyev/gpscripts">PARI/GP Scripts for Miscellaneous Math Problems</a> (invphi.gp).
%p A159953 read("transforms3") ; a054973 := BFILETOLIST("b054973.txt") ;
%p A159953 for i from 1 to 1000 do if op(i,a054973) > 1 then printf("%d,", op(i,a054973)) ; fi; od: # _R. J. Mathar_, May 22 2009
%t A159953 b[n_] := Sum[Boole[DivisorSigma[1, k] == n], {k, 1, n}];
%t A159953 Select[Array[b, 1000], # > 1&] (* _Jean-François Alcover_, Apr 06 2020 *)
%o A159953 (PARI) list(lim) = {my(s); for(k = 1, lim, s = invsigmaNum(k); if(s > 1, print1(s, ", ")));} \\ _Amiram Eldar_, Dec 25 2024, using _Max Alekseyev_'s invphi.gp
%Y A159953 Cf. A000203, A007609, A054973, A159886.
%K A159953 nonn
%O A159953 1,1
%A A159953 _Jaroslav Krizek_, Apr 27 2009
%E A159953 Edited and extended by _R. J. Mathar_, May 22 2009