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A097799 Number of partitions of the n-th deficient number into deficient numbers. 3

%I #6 Aug 02 2019 12:59:13

%S 1,2,3,5,7,14,20,27,37,49,85,111,143,184,234,374,585,727,899,1360,

%T 1664,2028,2985,4343,5218,6252,7474,8913,12591,14918,17639,24519,

%U 33836,39646,46377,54165,63162,85507,99276,115103,133276,154116,205308,272190

%N Number of partitions of the n-th deficient number into deficient numbers.

%H Amiram Eldar, <a href="/A097799/b097799.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DeficientNumber.html">Deficient Number</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Partition.html">Partition</a>

%t n = 60; d = Select[Range[n], DivisorSigma[1, #] < 2 # &]; CoefficientList[ Series[1/Product[1 - x^d[[i]], {i, 1, Length[d]}], {x, 0, n}], x][[d + 1]] (* _Amiram Eldar_, Aug 02 2019 *)

%Y Cf. A005100, A000041, A097797, A097800.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Aug 25 2004

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Last modified April 25 05:56 EDT 2024. Contains 371964 sequences. (Running on oeis4.)