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 A120641 Number of partitions of n into distinct double-free parts. 13
 1, 1, 1, 1, 2, 3, 2, 4, 5, 5, 7, 8, 10, 12, 14, 17, 20, 24, 26, 31, 38, 45, 50, 57, 68, 77, 88, 101, 116, 132, 151, 170, 194, 222, 247, 281, 318, 356, 399, 452, 509, 567, 635, 709, 794, 885, 983, 1094, 1222, 1358, 1504, 1671, 1854, 2050, 2264, 2505, 2771, 3060, 3370 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..400 Eric Weisstein's World of Mathematics, Double-Free Set EXAMPLE a(10) = #{10, 9+1, 8+2, 7+3, 6+4, 5+4+1, 5+3+2} = 7; a(11) = #{11, 10+1, 9+2, 8+3, 7+4, 7+3+1, 6+5, 6+4+1} = 8. MATHEMATICA Table[Length[Select[IntegerPartitions[n], UnsameQ@@#&&Intersection[#, 2*#]=={}&]], {n, 30}] (* Gus Wiseman, Jan 07 2019 *) CROSSREFS Cf. A000009, A050291, A101417, A303362, A320340, A323092, A323093, A323094. Sequence in context: A241255 A174625 A178853 * A008666 A240854 A286621 Adjacent sequences:  A120638 A120639 A120640 * A120642 A120643 A120644 KEYWORD nonn AUTHOR Reinhard Zumkeller, Aug 17 2006 EXTENSIONS a(0)=1 prepended by Alois P. Heinz, Jan 16 2019 STATUS approved

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Last modified January 19 12:36 EST 2020. Contains 331049 sequences. (Running on oeis4.)