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.

A319827 FDH numbers of relatively prime strict integer partitions.

This page as a plain text file.
%I A319827 #4 Sep 29 2018 12:57:57
%S A319827 2,6,8,10,12,14,18,20,21,22,24,26,28,30,32,33,34,35,38,40,42,44,46,48,
%T A319827 50,52,54,55,56,57,58,60,62,63,66,68,70,72,74,75,76,77,78,80,82,84,86,
%U A319827 88,90,91,93,94,95,96,98,99,100,102,104,105,106,108,110,112
%N A319827 FDH numbers of relatively prime strict integer partitions.
%C A319827 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 A319827 The sequence of all relatively prime strict integer partitions begins: (1), (2,1), (3,1), (4,1), (3,2), (5,1), (6,1), (4,3), (5,2), (7,1), (3,2,1), (8,1), (5,3), (4,2,1).
%t A319827 nn=200;
%t A319827 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 A319827 FDprimeList=Array[FDfactor,nn,1,Union];FDrules=MapIndexed[(#1->#2[[1]])&,FDprimeList];
%t A319827 Select[Range[nn],GCD@@(FDfactor[#]/.FDrules)==1&]
%Y A319827 Cf. A050376, A056239, A064547, A213925, A289508, A289509, A290103, A299755, A299757, A319826.
%K A319827 nonn
%O A319827 1,1
%A A319827 _Gus Wiseman_, Sep 28 2018