G.f. A(x) satisfies -2*x = Product_{n>=1} (1 - x^n/A(x)) * (1 - x^(n-1)*A(x)) * (1 + x^n).
A384272
G.f. A(x) satisfies -2*x = Product_{n>=1} (1 - x^n/A(x)) * (1 - x^(n-1)*A(x)) * (1 + x^n).
Terms
- a(0) =1a(1) =2a(2) =2a(3) =6a(4) =16a(5) =50a(6) =144a(7) =478a(8) =1510a(9) =5116a(10) =17034a(11) =58812a(12) =202166a(13) =709228a(14) =2489546a(15) =8848146a(16) =31525526a(17) =113236920a(18) =407983964a(19) =1478249454a(20) =5372468156a(21) =19607233026a(22) =71758722172a(23) =263480958508a(24) =969856453650
External references
- oeis: A384272