Length of list created by n substitutions k -> Range( -abs(k+1), abs(k-1), 2) starting with {1}.

A084075

Length of list created by n substitutions k -> Range( -abs(k+1), abs(k-1), 2) starting with {1}.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =12a(4) =33a(5) =86a(6) =249a(7) =680a(8) =2033a(9) =5722a(10) =17485a(11) =50260a(12) =156033a(13) =455534a(14) =1431281a(15) =4228752a(16) =13412193a(17) =40003058a(18) =127840085a(19) =384232156a(20) =1235575201a(21) =3737280582a(22) =12080678505a(23) =36736735672a(24) =119276490193a(25) =364372758986

External references