A296486 - OEIS

%I #4 Apr 13 2018 21:52:18

%S 5,8,5,9,9,9,6,6,2,9,8,4,4,6,4,4,0,3,1,2,8,6,0,3,5,7,7,5,8,6,0,5,4,2,

%T 6,0,8,8,1,6,1,8,8,8,4,6,3,9,7,2,6,3,6,1,0,1,9,6,8,1,0,0,1,8,7,9,9,3,

%U 6,3,9,4,8,0,6,9,6,5,7,1,0,4,5,7,9,5

%N Decimal expansion of limiting power-ratio for A295960; see Comments.

%C Suppose that A = (a(n)), for n >= 0, is a sequence, and g is a real number such that a(n)/a(n-1) -> g. The limiting power-ratio for A is the limit as n->oo of a(n)/g^n, assuming that this limit exists. For A = A295960, we have g = (1 + sqrt(5))/2, the golden ratio (A001622). See the guide at A296469 for related sequences.

%e limiting power-ratio = 5.859996629844644031286035775860542608816...

%t a[0] = 1; a[1] = 3; b[0] = 2; b[1 ] = 4; b[2] = 5;

%t a[n_] := a[n] = a[n - 1] + a[n - 2] + b[n] - 1;

%t j = 1; While[j < 13, k = a[j] - j - 1;

%t  While[k < a[j + 1] - j + 1, b[k] = j + k + 2; k++]; j++];

%t Table[a[n], {n, 0, k}]; (* A295960 *)

%t z = 2000; g = GoldenRatio; h = Table[N[a[n]/g^n, z], {n, 0, z}];

%t StringJoin[StringTake[ToString[h[[z]]], 41], "..."]

%t Take[RealDigits[Last[h], 10][[1]], 120]   (* A296486 *)

%Y Cf. A001622, A295960, A296284, A296485.

%K nonn,easy,cons

%O 1,1

%A _Clark Kimberling_, Apr 13 2018