Form array in which n-th row is obtained by expanding (1 + x + x^2)^n and taking the 4th column from the center.
A014533
Form array in which n-th row is obtained by expanding (1 + x + x^2)^n and taking the 4th column from the center.
Terms
- a(0) =1a(1) =5a(2) =21a(3) =77a(4) =266a(5) =882a(6) =2850a(7) =9042a(8) =28314a(9) =87802a(10) =270270a(11) =827190a(12) =2520336a(13) =7651632a(14) =23162976a(15) =69954048a(16) =210859245a(17) =634569201a(18) =1907165337a(19) =5725520801a(20) =17172595110a(21) =51465297950a(22) =154135675070a(23) =461366154990
External references
- oeis: A014533