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A328679 Heinz numbers of integer partitions with no two distinct parts relatively prime, but with no divisor in common to all of the parts. 3

%I #4 Nov 01 2019 18:41:47

%S 1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,17719,32768,

%T 40807,43381,50431,65536,74269,83143,101543,105703,116143,121307,

%U 123469,131072,139919,140699,142883,171613,181831,185803,191479,203557,205813,211381,213239

%N Heinz numbers of integer partitions with no two distinct parts relatively prime, but with no divisor in common to all of the parts.

%C Equals the union A000079 and A328868.

%C The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

%C A partition with no two distinct parts relatively prime is said to be intersecting.

%e The sequence of terms together with their prime indices begins:

%e 1: {}

%e 2: {1}

%e 4: {1,1}

%e 8: {1,1,1}

%e 16: {1,1,1,1}

%e 32: {1,1,1,1,1}

%e 64: {1,1,1,1,1,1}

%e 128: {1,1,1,1,1,1,1}

%e 256: {1,1,1,1,1,1,1,1}

%e 512: {1,1,1,1,1,1,1,1,1}

%e 1024: {1,1,1,1,1,1,1,1,1,1}

%e 2048: {1,1,1,1,1,1,1,1,1,1,1}

%e 4096: {1,1,1,1,1,1,1,1,1,1,1,1}

%e 8192: {1,1,1,1,1,1,1,1,1,1,1,1,1}

%e 16384: {1,1,1,1,1,1,1,1,1,1,1,1,1,1}

%e 17719: {6,10,15}

%e 32768: {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}

%e 40807: {6,14,21}

%e 43381: {6,15,20}

%e 50431: {10,12,15}

%e 65536: {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}

%t primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];

%t Select[Range[10000],#==1||GCD@@primeMS[#]==1&&And[And@@(GCD[##]>1&)@@@Subsets[Union[primeMS[#]],{2}]]&]

%Y These are the Heinz numbers of the partitions counted by A328672.

%Y Terms that are not powers of 2 are A328868.

%Y The strict case is A318716.

%Y The version without global relative primality is A328867.

%Y A ranking using binary indices (instead of prime indices) is A326912.

%Y The version for non-isomorphic multiset partitions is A319759.

%Y The version for divisibility (instead of relative primality) is A328677.

%Y Heinz numbers of relatively prime partitions are A289509.

%Y Cf. A000837, A056239, A112798, A200976, A202425, A289509, A291166, A302796, A316476, A318715, A319752, A328336.

%K nonn

%O 1,2

%A _Gus Wiseman_, Oct 30 2019

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Last modified April 23 18:16 EDT 2024. Contains 371916 sequences. (Running on oeis4.)