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A101049 Number of partitions of n into parts having at most two prime-factors. 5

%I #3 Mar 30 2012 18:50:48

%S 1,2,3,5,7,11,15,21,29,40,53,71,93,122,158,203,259,329,415,521,651,

%T 809,1001,1234,1515,1853,2258,2743,3321,4009,4825,5791,6932,8277,9859,

%U 11715,13889,16431,19398,22854,26873,31539,36949,43210,50446,58796,68419

%N Number of partitions of n into parts having at most two prime-factors.

%e n=10 has two partitions with parts having more than two

%e prime-factors: 10 = 2*2*2 + 2 = 2*2*2 + 1 + 1, therefore

%e a(10) = A000041(10) - 2 = 42 - 2 = 40.

%Y Cf. A000041, A101048, A037143, A101040.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Nov 28 2004

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Last modified April 23 15:11 EDT 2024. Contains 371914 sequences. (Running on oeis4.)