a(n) = a(n-1) + 3*a(n-2) - 2*a(n-3) - a(n-4) for n >= 4, where a(0) = 2, a(1) = 4, a(2) = 7, a(3) = 12.

A288317

a(n) = a(n-1) + 3*a(n-2) - 2*a(n-3) - a(n-4) for n >= 4, where a(0) = 2, a(1) = 4, a(2) = 7, a(3) = 12.

Terms

    a(0) =2a(1) =4a(2) =7a(3) =12a(4) =22a(5) =40a(6) =75a(7) =139a(8) =262a(9) =489a(10) =922a(11) =1726a(12) =3252a(13) =6097a(14) =11479a(15) =21540a(16) =40531a(17) =76096a(18) =143130a(19) =268816a(20) =505483a(21) =949575a(22) =1785262a(23) =3354205a(24) =6305358a(25) =11847874a(26) =22270276a(27) =41848977a(28) =78658699a(29) =147817204

External references