cp's OEIS Frontend

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.

A316361 FDH numbers of strict integer partitions such that not every distinct subset has a different average.

This page as a plain text file.
%I A316361 #6 Jun 30 2018 20:40:42
%S A316361 24,56,60,110,120,135,140,168,210,216,224,264,270,273,280,308,312,315,
%T A316361 330,342,360,378,384,408,420,440,456,459,480,504,520,540,546,550,552,
%U A316361 576,585,594,600,616,630,660,672,693,696,702,728,744,756,759,760,770,780
%N A316361 FDH numbers of strict integer partitions such that not every distinct subset has a different average.
%C A316361 Let f(n) = A050376(n) be the n-th Fermi-Dirac prime. The FDH number of a strict integer partition (y_1,...,y_k) is f(y_1)*...*f(y_k).
%e A316361 210 is the FDH number of (5,4,2,1), and the subsets {1,5}, and {2,4} have the same average, so 210 belongs to the data.
%t A316361 nn=1000;
%t A316361 FDfactor[n_]:=If[n==1,{},Sort[Join@@Cases[FactorInteger[n],{p_,k_}:>Power[p,Cases[Position[IntegerDigits[k,2]//Reverse,1],{m_}->2^(m-1)]]]]];
%t A316361 FDprimeList=Array[FDfactor,nn,1,Union];FDrules=MapIndexed[(#1->#2[[1]])&,FDprimeList];
%t A316361 Select[Range[nn],!UnsameQ@@Mean/@Union[Subsets[FDfactor[#]/.FDrules]]&]
%Y A316361 Cf. A050376, A064547, A108917, A213925, A275972, A299755, A299757, A301899, A301900, A316271, A316313, A316362.
%K A316361 nonn
%O A316361 1,1
%A A316361 _Gus Wiseman_, Jun 30 2018