a(n) = number of integer strings s(0),...,s(n) counted by array T in A026386 that have s(n)=0; also a(n) = T(2n,n).

A026387

a(n) = number of integer strings s(0),...,s(n) counted by array T in A026386 that have s(n)=0; also a(n) = T(2n,n).

Terms

    a(0) =2a(1) =8a(2) =34a(3) =150a(4) =678a(5) =3116a(6) =14494a(7) =68032a(8) =321590a(9) =1528776a(10) =7301142a(11) =35003238a(12) =168359754a(13) =812041860a(14) =3926147730a(15) =19022666310a(16) =92338836390a(17) =448968093320

External references