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Search: id:A060945
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%I A060945
%S A060945 1,2,3,6,10,18,31,55,96,169,296,520,912,1601,2809,4930,8651,15182,
%T A060945 26642,46754,82047,143983,252672,443409,778128,1365520
%N A060945 Number of ordered partitions of n into 1's, 2's and 4's.
%H A060945 Harry J. Smith, <a href="b060945.txt">Table of n, a(n) for n=1,...,500</
               a>
%F A060945 a(n) = a(n-1)+a(n-2)+a(n-4). G.f.: (x+x^2+x^4)/(1-x-x^2-x^4)
%o A060945 (PARI) { for (n=1, 500, if (n>4, a=a1 + a2 + a4; a4=a3; a3=a2; a2=a1; 
               a1=a, if (n==1, a=a4=1, if (n==2, a=a3=2, if (n==3, a=a2=3, a=a1=6)))); 
               write("b060945.txt", n, " ", a); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               Jul 15 2009]
%Y A060945 Cf. A000045 (1's and 2's only), A023359 (all powers of 2)
%Y A060945 Apart from n=0 term, same as unsigned version of A077930.
%Y A060945 Sequence in context: A066067 A121364 A102702 this_sequence A077930 A023359 
               A082482
%Y A060945 Adjacent sequences: A060942 A060943 A060944 this_sequence A060946 A060947 
               A060948
%K A060945 nonn
%O A060945 1,2
%A A060945 Len Smiley (smiley(AT)math.uaa.alaska.edu), May 07 2001

    
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Last modified December 7 23:50 EST 2009. Contains 170430 sequences.


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