Search: id:A006342 Results 1-1 of 1 results found. %I A006342 M3398 %S A006342 1,1,4,10,31,91,274,820,2461,7381,22144,66430,199291,597871, %T A006342 1793614,5380840,16142521,48427561,145282684,435848050,1307544151, %U A006342 3922632451,11767897354,35303692060,105911076181,317733228541 %N A006342 Coloring a circuit with 4 colors. %D A006342 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A006342 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %D A006342 F. R. Bernhart, Topics in Graph Theory Related to the Five Color Conjecture. Ph.D. Dissertation, Kansas State Univ., 1974. %D A006342 G. D. Birkhoff, D. C. Lewis, Chromatic polynomials. Trans. Amer. Math. Soc. 60, (1946). 355-451. %H A006342 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %H A006342 S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %F A006342 G.f.: (1 - 2 x ) / ( 1 - x^2 ) ( 1 - 3 x ). %F A006342 Binomial transform of A002001 (with interpolated zeros). Partial sums of A054878. E.g.f.: exp(x)(3cosh(2x)+1)/4; a(n)=3*3^n/8+1/4+3(-1)^n/ 8=sum{k=0..n, (3^k+3(-1)^k)/4 }. - Paul Barry (pbarry(AT)wit.ie), Sep 03 2003 %p A006342 A006342:=-(-1+2*z)/(z-1)/(3*z-1)/(z+1); [Conjectured by S. Plouffe in his 1992 dissertation.] %p A006342 a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=2*a[n-1]+3*a[n-2]-1 od: seq(a[n], n=1..26); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 28 2008 %Y A006342 Sequence in context: A145453 A034730 A095127 this_sequence A135831 A015796 A034717 %Y A006342 Adjacent sequences: A006339 A006340 A006341 this_sequence A006343 A006344 A006345 %K A006342 nonn %O A006342 0,3 %A A006342 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com) Search completed in 0.001 seconds