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A081332
Numbers having a unique partition into two 3-smooth numbers.
2
2, 3, 29, 31, 37, 41, 43, 49, 55, 58, 59, 62, 65, 67, 74, 83, 85, 86, 87, 89, 91, 93, 98, 109, 110, 111, 113, 116, 118, 123, 124, 130, 131, 134, 137, 147, 148, 155, 163, 165, 166, 170, 172, 174, 177, 178, 182, 186, 193, 195, 196, 201, 209, 217, 218, 220, 222, 226
OFFSET
1,1
FORMULA
A081326(a(n)) = 1.
MATHEMATICA
nmax = 1000;
S = Select[Range[nmax], Max[FactorInteger[#][[All, 1]]] <= 3 &];
P[n_] := IntegerPartitions[n, {2}, TakeWhile[S, # < n &]];
selQ[n_] := Length[P[n]] == 1;
Select[Range[nmax], selQ] (* Jean-François Alcover, Oct 14 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 19 2003
STATUS
approved