A049151 - OEIS

%I #6 Jul 24 2023 09:20:07

%S 1,1,3,9,33,127,519,2191,9509,42109,189571,864865,3989877,18580355,

%T 87227311,412371551,1961485449,9380593513,45078031763,217555637193,

%U 1054048424377,5124790576295,24996499042775,122278420437071

%N Recip transform of 2*(1 + x^3)-1/(1-x).

%C Sign diagram of generating sequence: +--+-----------...

%F D-finite with recurrence +43*n *(n-1) *(n-2)*(5307211695010*n +8087397530561) *(n+1)*a(n) +4*n*(n-1) *(n-2) *(500969612576475*n^2 -8318065279342961*n +18338013653749630)*a(n-1) -4*(n-1) *(n-2) *(6488460884022390*n^3 -73809744542730029*n^2 +257340541302438145*n -269280791373937752) *a(n-2) +4*(n-2) *(9846244502370420*n^4 -133765992121036340*n^3 +718862621109415290*n^2 -1721597503890605272*n +1518029237913933117) *a(n-3) +4*(18574051318071040*n^5 -325221606098140096*n^4 +2180597944239561168*n^3 -7047674106801530168*n^2 +11021508517018663148*n -6685167689303181687) *a(n-4) +4*(-35852044956631360*n^5 +705464161358090432*n^4 -5502698947195803020*n^3 +21252721236821515060*n^2 -40606225207653400515*n +30668461459305478053)*a(n-5) +240*(4*n-21) *(n-5)*(4*n-15)*(1443184123833*n -3908551467701)*(2*n-9)*a(n-6)=0. - _R. J. Mathar_, Jul 24 2023

%K nonn

%O 0,3

%A _Olivier Gérard_