Search: id:A032020 Results 1-1 of 1 results found. %I A032020 %S A032020 1,1,1,3,3,5,11,13,19,27,57,65,101,133,193,351,435,617,851,1177,1555, %T A032020 2751,3297,4757,6293,8761,11305,15603,24315,30461,41867,55741,74875, %U A032020 98043,130809,168425,257405,315973,431065,558327,751491,958265,1277867 %N A032020 Number of compositions (ordered partitions) of n into distinct parts. %C A032020 a(n)= the number of different ways to run up a staircase with n steps, taking steps of distinct sizes where the order matters and there is no other restriction on the number or the size of each step taken. - Mohammad K. Azarian (azarian(AT)evansville.edu), May 21 2008 %D A032020 B. Richmond and A. Knopfmacher, Compositions with distinct parts, Aequationes Mathematicae 49 (1995), pp. 86-97. %D A032020 Mohammad K. Azarian, A Generalization of the Climbing Stairs Problem II, Missouri Journal of Mathematical Sciences, Vol. 16, No. 1, Winter 2004, pp. 12-17. %H A032020 T. D. Noe, Table of n, a(n) for n=0..1000 %H A032020 C. G. Bower, Transforms (2) %F A032020 "AGK" (ordered, elements, unlabeled) transform of 1, 1, 1, 1... %F A032020 G.f.: Sum(k >= 0; k! x^((k^2+k)/2) / Prod(1<=j<=k; 1-x^j)) - David W. Wilson (davidwwilson(AT)comcast.net) May 04 2000 %e A032020 a(6) = 11 because 6 = 5+1 = 4+2 = 3+2+1 = 3+1+2 = 2+4 = 2+3+1 = 2+1+3 = 1+5 = 1+3+2 = 1+2+3 %Y A032020 Cf. A003242, A032011. %Y A032020 Sequence in context: A100886 A072337 A132751 this_sequence A084656 A073749 A146918 %Y A032020 Adjacent sequences: A032017 A032018 A032019 this_sequence A032021 A032022 A032023 %K A032020 nonn,easy,nice %O A032020 0,4 %A A032020 Christian G. Bower (bowerc(AT)usa.net), Apr 01 1998 Search completed in 0.001 seconds