login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A296433
Decimal expansion of ratio-sum for A296288; see Comments.
1
7, 0, 9, 3, 8, 8, 3, 2, 4, 4, 5, 5, 8, 2, 3, 3, 2, 8, 2, 5, 1, 8, 6, 3, 2, 9, 3, 3, 3, 3, 8, 1, 5, 1, 2, 8, 8, 8, 5, 0, 3, 6, 1, 6, 9, 3, 0, 3, 9, 2, 1, 8, 1, 5, 6, 0, 9, 5, 1, 9, 9, 8, 2, 3, 1, 8, 2, 1, 8, 1, 7, 8, 3, 0, 2, 7, 3, 2, 6, 6, 5, 4, 3, 0, 4, 2
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 = A296288 we have g = (1 + sqrt(5))/2, the golden ratio (A001622). See A296425-A296434 for related ratio-sums and A296452-A296461 for related limiting power-ratios.
EXAMPLE
Ratio-sum = 7.093883244558233282518632...
MATHEMATICA
a[0] = 1; a[1] = 2; b[0] = 3; b[1] = 4;
a[n_] := a[n] = a[n - 1] + a[n - 2] + n*b[n - 2];
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}]; (* A296288 *)
g = GoldenRatio; s = N[Sum[- g + a[n]/a[n - 1], {n, 1, 1000}], 200]
Take[RealDigits[s, 10][[1]], 100] (* A296433 *)
CROSSREFS
Sequence in context: A234355 A021145 A269404 * A021589 A093444 A369522
KEYWORD
nonn,easy,cons
AUTHOR
Clark Kimberling, Dec 15 2017
STATUS
approved