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 1-5 of 5 results.

A010709 Constant sequence: the all 4's sequence.

Original entry on oeis.org

4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
Offset: 0

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Author

Keywords

Comments

From Klaus Brockhaus, May 25 2010: (Start)
Continued fraction expansion of 2+sqrt(5).
Decimal expansion of 4/9.
Inverse binomial transform of A020707. (End)

Crossrefs

From Klaus Brockhaus, May 25 2010: (Start)
Equals 4*A000012, 2*A007395, A010731/2, A010855/4, A010871/8.
Cf. A098317 (decimal expansion of 2+sqrt(5)), A020707 (2^(n+2)). (End)

Programs

Formula

From Klaus Brockhaus, May 25 2010: (Start)
a(n) = 4.
G.f.: 4/(1-x). (End)
E.g.f.: 4*e^x. - Vincenzo Librandi, Jan 29 2012

A040056 Continued fraction for sqrt(65).

Original entry on oeis.org

8, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16
Offset: 0

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Author

Keywords

Examples

			8.06225774829854965236661... = 8 + 1/(16 + 1/(16 + 1/(16 + 1/(16 + ...)))).
		

Crossrefs

Cf. A010517 (decimal expansion), A041112/A041113 (convergents), A248289 (Egyptian fraction).

Programs

  • Maple
    Digits := 100: convert(evalf(sqrt(N)),confrac,90,'cvgts'):
  • Mathematica
    ContinuedFraction[Sqrt[65],300] (* Vladimir Joseph Stephan Orlovsky, Mar 08 2011 *)
    PadRight[{8},120,{16}] (* Harvey P. Dale, Nov 27 2020 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 49000); x=contfrac(sqrt(65)); for (n=0, 20000, write("b040056.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 07 2009

Formula

From Elmo R. Oliveira, Feb 10 2024: (Start)
a(n) = 16 = A010855(n) for n >= 1.
G.f.: 8*(1+x)/(1-x).
E.g.f.: 16*exp(x) - 8.
a(n) = 8*A040000(n) = 4*A040002(n) = 2*A040012(n). (End)

A177499 Period 4: repeat [1, 16, 4, 16].

Original entry on oeis.org

1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16, 1, 16, 4, 16
Offset: 0

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Author

Paul Curtz, May 10 2010

Keywords

Comments

From Klaus Brockhaus, May 14 2010: (Start)
Interleaving of A000012, A010855, A010709 and A010855.
Continued fraction expansion of (44+sqrt(2442))/88. (End)

Crossrefs

Programs

Formula

From Klaus Brockhaus, May 14 2010: (Start)
a(n+2) - a(n) = A010674(n).
a(n) = a(n-4) for n > 3.
G.f.: (1+16*x+4*x^2+16*x^3)/(1-x^4). (End)
a(n) = A176895(n)^2. - Paul Curtz, Mar 21 2011
a(n) = (37 - 6*cos(n*Pi/2) - 27*cos(n*Pi) - 27*I*sin(n*Pi))/4. - Wesley Ivan Hurt, Jul 09 2016

A023014 Number of partitions of n into parts of 16 kinds.

Original entry on oeis.org

1, 16, 152, 1088, 6460, 33440, 155584, 663936, 2636326, 9845040, 34861152, 117809728, 381946360, 1193074144, 3603543040, 10556065152, 30068145905, 83466484112, 226236086512, 599785472000, 1557643542308, 3967888347232, 9926348625408, 24413219138816
Offset: 0

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Keywords

Comments

a(n) is Euler transform of A010855. - Alois P. Heinz, Oct 17 2008

Crossrefs

Cf. 16th column of A144064. - Alois P. Heinz, Oct 17 2008

Programs

  • Maple
    with (numtheory): a:= proc(n) option remember; `if`(n=0, 1, add (add (d*16, d=divisors(j)) *a(n-j), j=1..n)/n) end: seq (a(n), n=0..40); # Alois P. Heinz, Oct 17 2008
  • Mathematica
    CoefficientList[Series[1/QPochhammer[x]^16, {x, 0, 30}], x] (* Indranil Ghosh, Mar 27 2017 *)
  • PARI
    Vec(1/eta(x)^16 + O(x^30)) \\ Indranil Ghosh, Mar 27 2017

Formula

G.f.: Product_{m>=1} 1/(1-x^m)^16.
a(0) = 1, a(n) = (16/n)*Sum_{k=1..n} A000203(k)*a(n-k) for n > 0. - Seiichi Manyama, Mar 27 2017
a(n) ~ m^((m+1)/4) * exp(Pi*sqrt(2*m*n/3)) / (2^((3*m+5)/4) * 3^((m+1)/4) * n^((m+3)/4)) * (1 - ((9+Pi^2)*m^2+36*m+27) / (24*Pi*sqrt(6*m*n))), set m = 16. - Vaclav Kotesovec, Jun 28 2025

A187541 a(4n+2) = 2n+1, otherwise a(n) = 4n.

Original entry on oeis.org

0, 4, 1, 12, 16, 20, 3, 28, 32, 36, 5, 44, 48, 52, 7, 60, 64, 68, 9, 76, 80, 84, 11, 92, 96, 100, 13, 108, 112, 116, 15, 124, 128, 132, 17, 140, 144, 148, 19, 156, 160, 164, 21, 172, 176, 180, 23, 188, 192, 196, 25, 204, 208, 212, 27, 220, 224, 228, 29, 236, 240, 244, 31, 252
Offset: 0

Views

Author

Paul Curtz, Mar 11 2011

Keywords

Crossrefs

Programs

Formula

a(n) = 2*a(n-4) - a(n-8) for n>7.
G.f.: x*(4+x+12*x^2+16*x^3+12*x^4+x^5+4*x^6)/(1-x^4)^2; a(n) = (n/8)*(32 -7*(1+(-1)^n)*(1-i^n)) where i=sqrt(-1). - Bruno Berselli, Mar 15 2011
From Paul Curtz, Mar 22 2011: (Start)
A060819(n)*a(n) = 0,4,1,36,16,100, = 0,4, followed by A061038(n+2).
a(n) = a(n-4) + period 4: repeat [16, 16, 2, 16]. Note that a(n) = 4*n/(period 4: repeat [1, 1, 8, 1]), Hence 16's = A010855. (End)
a(n) = 16*n/(11+7*(I^(2*n)-I^(-n)-I^n)). - Wesley Ivan Hurt, Jul 05 2016

Extensions

Edited by N. J. A. Sloane, Mar 15 2011
Showing 1-5 of 5 results.