Row sums of triangle A099514, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + z + 2*z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.
A099515
Row sums of triangle A099514, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + z + 2*z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =13a(4) =31a(5) =78a(6) =190a(7) =469a(8) =1150a(9) =2825a(10) =6933a(11) =17015a(12) =41754a(13) =102454a(14) =251393a(15) =616826a(16) =1513453a(17) =3713389a(18) =9111087a(19) =22354678a(20) =54848638a(21) =134574493a(22) =330186518a(23) =810131889a(24) =1987705301a(25) =4876948743a(26) =11965871650a(27) =29358946070a(28) =72033839657
External references
- oeis: A099515