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A168173
Number of partitions of n in which the sum of reciprocals of parts is less than 1.
0
0, 1, 1, 1, 2, 3, 3, 4, 4, 6, 8, 12, 13, 16, 18, 21, 25, 32, 38, 46, 55, 65, 78, 92, 103, 122, 140, 165, 193, 229, 264, 305, 345, 395, 451, 517, 590, 682, 781, 893, 1013, 1165, 1324, 1518, 1717, 1945, 2188, 2468, 2753, 3089, 3457, 3865, 4321, 4856, 5441, 6108, 6831
OFFSET
1,5
MAPLE
a := proc (n) local P, ct, j: with(combinat): P := partition(n): ct := 0: for j to numbpart(n) do if add(1/P[j][i], i = 1 .. nops(P[j])) < 1 then ct := ct+1 else end if end do: ct end proc: seq(a(n), n = 1 .. 60); # Emeric Deutsch, Dec 02 2009
MATHEMATICA
Table[Count[IntegerPartitions[n], _?(Total[1/#]<1&)], {n, 60}] (* Harvey P. Dale, Dec 14 2012 *)
CROSSREFS
Cf. A051908.
Sequence in context: A267597 A238221 A320052 * A095916 A130121 A007898
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Nov 19 2009
EXTENSIONS
Extended by Emeric Deutsch, Dec 02 2009
STATUS
approved