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 A226119 #16 May 28 2013 13:30:21 %S A226119 1,6,36,64,105,114,135,1980,2016,3072,5120,7056,7840,9216,16320,18720, %T A226119 18900,23100,23622,24003,25536,26088,26733,28455,29078,29337,29700, %U A226119 29760,30597,30894,30912,31155,31496,31758,32361,33782,34020,34286,36000,36036,36099 %N A226119 Numbers such that sigma(phi(tau(n)))=tau(phi(sigma(n))). %H A226119 Paolo P. Lava and T. D. Noe, <a href="/A226119/b226119.txt">Table of n, a(n) for n = 1..1000</a> (first 270 terms from Paolo P. Lava) %e A226119 29337 is in the sequence since: %e A226119 sigma(29337)=49152 -> phi(49152)=16384 -> tau(16384)=15. %e A226119 tau(29337)=16 -> phi(16)=8 -> sigma(8)=15. %p A226119 with(numtheory); A226119:=proc(q) local n; %p A226119 for n from 1 to q do %p A226119 if sigma(phi(tau(n)))=tau(phi(sigma(n))) then print(n); %p A226119 fi; od; end: A226119(10^6); %t A226119 Select[Range[36099], DivisorSigma[1, EulerPhi[DivisorSigma[0, #]]] == DivisorSigma[0, EulerPhi[DivisorSigma[1, #]]] &] (* _T. D. Noe_, May 28 2013 *) %Y A226119 Cf. A000005, A000010, A000203, A033632, A067160, A076361, A226117, A226118. %K A226119 nonn %O A226119 1,2 %A A226119 _Paolo P. Lava_, May 27 2013