0,3

D. Callan, T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 [math.CO] (2017), Table 1 No 180.

D-finite with recurrence n*(385609*n-2095145)*a(n) +(-5644101*n^2+36106145*n-27042972)*a(n-1) +(33091613*n^2-244146701*n+323980392)*a(n-2) +8*(-12573004*n^2+104897321*n-186239709)*a(n-3) +2*(86257019*n^2-797381679*n+1686603678)*a(n-4) +(-170919433*n^2+1719014757*n-4076783688)*a(n-5) +2*(48248905*n^2-521535307*n+1343951034)*a(n-6) +12*(-2413672*n^2+27798510*n-76388463)*a(n-7) +24*(75470*n-357743)*(2*n-15)*a(n-8) +8*(-44591*n+289284)=0. - R. J. Mathar, Mar 11 2025

C := (1-sqrt(1-4*x))/2/x ;

(1 -7*x +18*x^2 -22*x^3 +16*x^4 -6*x^5 +x^6 -(x -5*x^2 +8*x^3 -2*x^4 -2*x^5 +x^6)*C)/((1 -2*x)*(1 -x)^2*(1 -5*x +4*x^2 -x^3)) ;

taylor(%, x=0, 40) ;

gfun[seriestolist](%) ;

Sequence in context: A116823 A289597 A116743 * A263790 A247416 A105872

Adjacent sequences: A294813 A294814 A294815 * A294817 A294818 A294819

nonn,easy

R. J. Mathar, Nov 09 2017

approved