A325196 Heinz numbers of integer partitions such that the difference between the length of the minimal triangular partition containing and the maximal triangular partition contained in the Young diagram is 1.
3, 4, 9, 10, 12, 15, 18, 20, 42, 45, 50, 60, 63, 70, 75, 84, 90, 100, 105, 126, 140, 150, 294, 315, 330, 350, 420, 441, 462, 490, 495, 525, 550, 588, 630, 660, 693, 700, 735, 770, 825, 882, 924, 980, 990, 1050, 1100, 1155, 1386, 1470, 1540, 1650, 2730, 3234
Offset: 1
Keywords
Examples
The sequence of terms together with their prime indices begins: 3: {2} 4: {1,1} 9: {2,2} 10: {1,3} 12: {1,1,2} 15: {2,3} 18: {1,2,2} 20: {1,1,3} 42: {1,2,4} 45: {2,2,3} 50: {1,3,3} 60: {1,1,2,3} 63: {2,2,4} 70: {1,3,4} 75: {2,3,3} 84: {1,1,2,4} 90: {1,2,2,3} 100: {1,1,3,3} 105: {2,3,4} 126: {1,2,2,4}
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Programs
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Mathematica
primeptn[n_]:=If[n==1,{},Reverse[Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]]; otb[ptn_]:=Min@@MapIndexed[#1+#2[[1]]-1&,Append[ptn,0]]; otbmax[ptn_]:=Max@@MapIndexed[#1+#2[[1]]-1&,Append[ptn,0]]; Select[Range[1000],otbmax[primeptn[#]]-otb[primeptn[#]]==1&]
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