Number of ways to represent n as a+b*(c+d*(e+f*(...x+y*(z)...))) in positive integers.

Terms

a(0) =1a(1) =2a(2) =5a(3) =11a(4) =25a(5) =51a(6) =110a(7) =221a(8) =456a(9) =918a(10) =1864a(11) =3729a(12) =7528a(13) =15057a(14) =30227a(15) =60485a(16) =121205a(17) =242411a(18) =485337a(19) =970675a(20) =1942307a(21) =3884730a(22) =7771327a(23) =15542655a(24) =31089330a(25) =62178686a(26) =124364903a(27) =248730268a(28) =497475717a(29) =994951435