%I A038201
%S A038201 1,1,1,1,1,2,3,4,5,9,12,14,15,29,41,50,55,105,146,175,190,365,511,616,
%T A038201 671,1287,1798,2163,2353,4516,6314,7601,8272,15873,22187,26703,29056,
%U A038201 55759,77946,93819,102091,195910,273856,329615,358671,688286,962142
%N A038201 5-wave sequence.
%C A038201 a(4n) forms A006358. A second recurrence formula is: a(n)=3a(n-4)+3a(n-8)-4a(n-12)-a(n-16)+a(n-20).
%C A038201 Sequence of perfect distributions for a cascade merge with six tapes 
               according to Knuth. - Michael Somos Feb 07 2004
%D A038201 D. E. Knuth, Art of Computer Programming, Vol. 3, Sect. 5.4.3, Eq. (1).
%H A038201 F. v. Lamoen, <a href="http://home.wxs.nl/~lamoen/wiskunde/wave.htm">
               Wave sequences</a>
%F A038201 a(n)=a(n-1)+a(n-2) if n=4m+1, a(n)=a(n-1)+a(n-4) if n=4m+2, a(n)=a(n-1)+a(n-6) 
               if n=4m+3 and a(n)=a(n-1)+a(n-8) if n=4m.
%F A038201 G.f.: -(1+x+x^2+x^3-2*x^4-x^5+x^7-x^8-x^11+x^12)/(-1+3*x^4+3*x^8-4*x^12-x^16+x^20)
%o A038201 (PARI) a(n)=local(m);if(n<=0,n==0,m=(n-1)\4*4;sum(k=2*m-n,m,a(k)))
%Y A038201 Cf. A038196, A038197.
%Y A038201 Sequence in context: A093305 A065817 A084542 this_sequence A033084 A076134 
               A101526
%Y A038201 Adjacent sequences: A038198 A038199 A038200 this_sequence A038202 A038203 
               A038204
%K A038201 easy,nonn
%O A038201 0,6
%A A038201 Floor van Lamoen (fvlamoen(AT)hotmail.com)
%E A038201 Edited by Floor van Lamoen (fvlamoen(AT)hotmail.com), Feb 05 2002