cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A298512 Decimal expansion of lim_ {n->oo} ((n + 1)*g - s(0) - s(1) - ... - s(n)), where g = (1 + sqrt (5))/2, s(n) = (s(n - 1) + 1)^(1/2), s(0) = 1.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Feb 11 2018

Keywords

Comments

Lim_{n->oo} s(n) = g = golden ratio, A001622. In the following guide to related sequences, the sequence gives the decimal expansion for lim_{n->oo} |(n+1)*g - s(0) - s(1) - ... - s(n)|, where s(n) = (s(n-1) + d)^p, and tau = (1+sqrt(5))/2.
***
sequence d p a(0) g
A298512 1 1/2 1 (1+sqrt(5))/2
A298513 1 1/2 2 (1+sqrt(5))/2
A298514 1 1/2 3 (1+sqrt(5))/2
A298515 1/2 1/2 1 (1+sqrt(3))/2
A298516 2 1/2 1 2
A298517 3 1/2 1 (1+sqrt(13))/2
A298518 1 1/3 1 1.3247...
A298519 1 1/3 2 1.3247...
A298520 1 1/3 3 1.3247...
A298521 1 2/3 1 2.1478...
A298522 tau 1/2 1 1.8667...
A298523 tau 1/2 2 1.8667...
A298524 sqrt(2) 1/2 1 1.7900...
A298525 sqrt(2) 1/2 2 1.7900...
A298526 sqrt(3) 1/2 1 1.9078...
A298527 sqrt(3) 1/2 2 1.9078...
A298528 e 1/2 1 2.2228...
A298529 e 1/2 e 2.2228...
A298530 Pi 1/2 1 2.3416...
A298531 Pi 1/2 Pi 2.3416...
A298532 tau 1/2 tau 2.3416...

Examples

			s(n) = (1, 1.4142..., 1.5537..., 1.5980..., 1.6118..., ...) with limit g = 1.618... = (1+sqrt(5))/2.
((n + 1)*g - s(0) - s(1) - ... - s(n)) -> 0.9150498480151349148436312146030...
		

Crossrefs

Programs

  • Mathematica
    s[0] = 1; d = 1; p = 1/2; s[n_] := s[n] = (s[n - 1] + d)^p
    N[Table[s[n], {n, 0, 30}]]
    z = 200 ; g = GoldenRatio; s = N[(z + 1)*g - Sum[s[n], {n, 0, z}], 150 ];
    RealDigits[s, 10][[1]];  (* A298512 *)

A275828 Decimal expansion of the nested surd sqrt(phi + sqrt(phi + sqrt(phi + sqrt(phi + ... )))) where phi is golden ratio = (1 + sqrt(5))/2; see A001622.

Original entry on oeis.org

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

Views

Author

Jaroslav Krizek, Aug 10 2016

Keywords

Comments

Also decimal expansion of (1 + (sqrt(1 + 4*((1 + sqrt(5)) / 2)))) / 2.
Sequence with a(1) = 0 is decimal expansion of the nested surd sqrt(phi - sqrt(phi - sqrt(phi - sqrt(phi - ...)))) where phi is golden ratio = (1 + sqrt(5))/2; see A001622.
Solution of y^2 - y - phi = 0.

Examples

			1.866760399173862092990872...
		

Crossrefs

Programs

  • Mathematica
    u = N[(1/2) (1 + Sqrt[3 + 2*Sqrt[5]]), 100]
    RealDigits[u][[1]] (* Clark Kimberling, Jan 25 2018 *)

Formula

Equals (1/2)*(1+sqrt(3+2*sqrt(5))). - Clark Kimberling, Jan 25 2018

Extensions

Terms corrected by Clark Kimberling, Jan 25 2018

A298523 Decimal expansion of lim_ {n->oo} (s(0) + s(1) + ... + s(n) - (n + 1)*g), where g = 1.86676039917386..., s(n) = (s(n - 1) + (1+sqrt(5))/2)^(1/2), s(0) = 2.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Feb 12 2018

Keywords

Comments

(lim_ {n->oo} s(n)) = g = real zero of x^2 - x - (1+sqrt(5))/2. See A298512 for a guide to related sequences.

Examples

			s(0) + s(1) + ... + s(n) - (n + 1)*g -> 0.1814900833342507808225393126374219...
		

Crossrefs

Programs

  • Mathematica
    s[0] = 2; d = GoldenRatio; p = 1/2;
    g = (x /. NSolve[x^(1/p) - x - d == 0, x, 200])[[2]]
    s[n_] := s[n] = (s[n - 1] + d)^p
    N[Table[s[n], {n, 0, 30}]]
    s = N[Sum[- g + s[n], {n, 0, 200}], 150 ];
    RealDigits[s, 10][[1]] (* A298523 *)

A298738 Decimal expansion of (1/2)(1 + sqrt(7 + 2*sqrt(5))).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Feb 13 2018

Keywords

Examples

			constant = 2.1935270853310539386... = positive zero of x^2 - x - r^2, where r = golden ratio = (1+ sqrt(5))/2; see A001622.
		

Crossrefs

Programs

  • Mathematica
    r = (1/2)*(1 + Sqrt[7 + 2*Sqrt[5]])
    RealDigits[N[r, 100], 10][[1]];  (* A298738 *)
    RealDigits[(1+Sqrt[7+2*Sqrt[5]])/2,10,120][[1]] (* Harvey P. Dale, Jun 13 2025 *)
Showing 1-4 of 4 results.