# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a100927 Showing 1-1 of 1 %I A100927 #12 Jan 27 2019 09:54:12 %S A100927 1,0,1,1,1,2,1,3,2,4,4,5,7,7,10,10,13,15,17,21,23,29,32,38,44,50,59, %T A100927 66,76,87,100,113,129,147,167,189,214,241,273,307,345,388,436,489,548, %U A100927 612,686,765,854,951,1059,1180,1309,1456,1614,1791,1985,2196 %N A100927 Number of partitions of n into distinct parts free of hexagonal numbers. %C A100927 This is also the inverted graded of the generating function of partitions into parts free of hexagonal numbers %H A100927 Noureddine Chair, Partition Identities From Partial Supersymmetry, arXiv:hep-th/0409011v1, 2004. %H A100927 James A. Sellers, Partitions Excluding Specific Polygonal Numbers As Parts, Journal of Integer Sequences, Vol. 7 (2004), Article 04.2.4. %F A100927 G.f.:=product_{k>0}(1+x^k)/(1+x^(2k^2-k))= 1/product_{k>0}(1-x^k+x^(2k)-x^(3k)+...-x^(2k^2-3k)+x^(2k^2-2k)) %e A100927 E.g"a(16)=13 because 16=14+2=13+3=12+4=11+5=11+3+2=10+4+2=9+7=9+5+2=9+4+3=8+5+3=7+5+4=7+4+3+2" %p A100927 series(product((1+x^k)/(1+x^(2*k^(2)-k)),k=1..100),x=0,100); %K A100927 nonn %O A100927 1,6 %A A100927 _Noureddine Chair_, Nov 22 2004 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE