A296489 Decimal expansion of ratio-sum for A293358; see Comments.

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

Offset

1,1

Comments

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 ratio-sum for A is |a(1)/a(0) - g| + |a(2)/a(1) - g| + ..., assuming that this series converges. For A = A293358, we have g = (1 + sqrt(5))/2, the golden ratio (A001622). See the guide at A296469 for related sequences.

Links

Table of n, a(n) for n=1..86.

Example

ratio-sum = 3.535917393515259350716802232248550673355...

Mathematica

a[0] = 1; a[1] = 3; b[0] = 2; b[1 ] = 4;
a[n_] := a[n] = a[n - 1] + a[n - 2] + b[n - 1];
j = 1; While[j < 13, k = a[j] - j - 1;
While[k < a[j + 1] - j + 1, b[k] = j + k + 2; k++]; j++];
Table[a[n], {n, 0, k}]; (* A293358 *)
g = GoldenRatio; s = N[Sum[- g + a[n]/a[n - 1], {n, 1, 1000}], 200]
Take[RealDigits[s, 10][[1]], 100]  (* A296489 *)

Crossrefs

Cf. A001622, A293358, A296284, A296490.

Sequence in context: A364564 A188889 A219604 * A253398 A151568 A134429

Adjacent sequences: A296486 A296487 A296488 * A296490 A296491 A296492

Keyword

nonn,easy,cons

Author

Clark Kimberling, Dec 19 2017

Status

approved