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A316267 FDH numbers of strict integer partitions of prime numbers with a prime number of prime parts. 2

%I #5 Jun 29 2018 11:35:32

%S 12,21,57,123,249,417,532,699,867,1100,1389,1463,1509,1708,2049,2068,

%T 2307,2324,2913,3116,3147,3157,3273,3325,3619,3903,4227,4268,4636,

%U 4821,5079,5225,5324,5516,5739,6308,6391,6524,6621,6644,7469,8092,8193,8225,8457

%N FDH numbers of strict integer partitions of prime numbers with a prime number of prime parts.

%C 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 Sequence of strict integer partitions of prime numbers with a prime number of prime parts, preceded by their FDH numbers, begins:

%e 12: (3,2)

%e 21: (5,2)

%e 57: (11,2)

%e 123: (17,2)

%e 249: (29,2)

%e 417: (41,2)

%e 532: (11,5,3)

%e 699: (59,2)

%e 867: (71,2)

%e 1100: (13,7,3)

%e 1389: (101,2)

%e 1463: (11,7,5)

%e 1509: (107,2)

%e 1708: (23,5,3)

%t nn=1000;

%t 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 FDprimeList=Array[FDfactor,nn,1,Union];FDrules=MapIndexed[(#1->#2[[1]])&,FDprimeList];

%t Select[Range[nn],And[PrimeQ[Total[FDfactor[#]/.FDrules]],PrimeQ[Length[FDfactor[#]]],And@@PrimeQ/@(FDfactor[#]/.FDrules)]&]

%Y Cf. A000586, A045450, A050376, A064547, A213925, A299755, A299757, A316185, A316265, A316266.

%K nonn

%O 1,1

%A _Gus Wiseman_, Jun 28 2018

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)