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 A256248 #28 Jun 01 2015 23:49:19
%S A256248 1,2,3,4,6,10,14,20,29,41,57,79,110,153,210,286,392,534,723,982,1330,
%T A256248 1790,2415,3249,4359,5838,7824,10457,13949,18581,24724,32848,43568,
%U A256248 57723,76429,101095,133599,176414,232772,306920,404256,532034,699655,919551,1207627
%N A256248 Indices of powers of two in A055744 (the sequence of n that have the same prime power set as phi(n)).
%C A256248 All powers of 2, including 1, but excluding 2 itself (A151821) are terms of A055744.
%C A256248 This sequence lists the positions of A151821 terms within A055744.
%C A256248 Is a(n+1)/a(n) ~ 4/3 for large n? - _David A. Corneth_, Mar 21 2015
%C A256248 A209229(A055744(a(n))) = 1. - _Reinhard Zumkeller_, Jun 01 2015
%H A256248 Hiroaki Yamanouchi, <a href="/A256248/b256248.txt">Table of n, a(n) for n = 1..50</a>
%H A256248 Paul Pollack and Carl Pomerance, <a href="http://www.emis.de/journals/INTEGERS/papers/a14self/a14self.Abstract.html">Prime-Perfect Numbers</a>, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 12a, Paper A14, 2012.
%e A256248 The first terms of A055744 are 1, 4, 8, 16, 18, 32, among which 18 is the only integer that is not a power of 2. Thus this sequence starts with 1, 2, 3, 4, 6.
%t A256248 t = Select[Range@ 1000000, First /@ FactorInteger@# == First /@ FactorInteger@ EulerPhi@ # &]; f[n_] := Block[{pf = FactorInteger@ n, p2}, p2 = First@ First@ pf; If[Length@ pf == 1 && First@ First@ pf == 2, Last@ First@ pf, 0]]; {1}~Join~Flatten@ Position[f /@ t, n_ /; n > 0] (* _Michael De Vlieger_, Mar 21 2015 *)
%o A256248 (PARI) lista(nn) = {nb = 0; for (n=1, nn, if (factor(n)[, 1]==factor(eulerphi(n))[, 1], nb++; if (n == 2^valuation(n, 2), print1(nb, ", "));););}
%o A256248 (Haskell)
%o A256248 a256248 n = a256248_list !! (n-1)
%o A256248 a256248_list = filter ((== 1) . a209229 . a055744) [1..]
%o A256248 -- _Reinhard Zumkeller_, Jun 01 2015
%Y A256248 Cf. A055744, A151821.
%Y A256248 Cf. A209229.
%K A256248 nonn
%O A256248 1,2
%A A256248 _Michel Marcus_, Mar 20 2015
%E A256248 a(30)-a(45) from _Hiroaki Yamanouchi_, Mar 31 2015