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.

A029920 Convert n from centimeters (cm) to inches (").

Original entry on oeis.org

0, 0, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 15, 16, 16, 17, 17, 17, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 22, 22, 22, 23, 23, 24, 24, 24, 25, 25, 26, 26, 26, 27, 27, 28, 28
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 8.

Links

Crossrefs

Cf. A085269 (with floor), A029919.

Programs

A085270 Integer part of the conversion from miles to kilometers.

Original entry on oeis.org

0, 1, 3, 4, 6, 8, 9, 11, 12, 14, 16, 17, 19, 20, 22, 24, 25, 27, 28, 30, 32, 33, 35, 37, 38, 40, 41, 43, 45, 46, 48, 49, 51, 53, 54, 56, 57, 59, 61, 62, 64, 65, 67, 69, 70, 72, 74, 75, 77, 78, 80, 82, 83, 85, 86, 88, 90, 91, 93, 94, 96, 98, 99, 101, 102, 104, 106, 107, 109, 111
Offset: 0

Views

Author

Cino Hilliard, Aug 12 2003

Keywords

Crossrefs

Cf. A085269.

Programs

  • PARI
    f(n) = for(x=0,n,print1(floor(x*12*5280*2.54/10e4),","))

A173276 a(n) = a(n-2) + a(n-3) - floor(a(n-3)/2) - floor(a(n-4)/2).

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 5, 5, 5, 6, 6, 7, 7, 7, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 15, 16, 16, 17, 17, 17, 18, 18, 19, 19, 19, 20, 20, 21, 21, 21, 22, 22, 23, 23, 23, 24, 24, 25, 25, 25, 26, 26, 27, 27, 27, 28, 28
Offset: 0

Views

Author

Roger L. Bagula, Nov 22 2010

Keywords

Comments

Instead of the Fibonacci sequence this has the base Padovan sequence.
The a(n+1)/a(n) ratio approaches one.

Links

Crossrefs

Cf. A000931 (Padovan), A085269.

Programs

  • Magma
    [Floor((2*n+5)/5) : n in [0..50]]; // Wesley Ivan Hurt, Mar 15 2015
  • Maple
    A173276:=n->floor((2*n+5)/5): seq(A173276(n), n=0..50); # Wesley Ivan Hurt, Mar 15 2015
  • Mathematica
    f[-2] = 0; f[-1] = 0; f[0] = 1; f[1] = 1;
f[n_] := f[n] = f[n - 2] + f[n - 3] - Floor[f[n - 3]/2] - Floor[f[n - 4]/2]
Table[f[n], {n, 0, 50}]
nxt[{a_,b_,c_,d_}]:={b,c,d,c+b-Floor[b/2]-Floor[a/2]}; NestList[nxt,{1,1,1,2},70][[;;,1]] (* Harvey P. Dale, Jul 30 2023 *)
  • PARI
    vector(100,n,(2*n+3)\5) \\ Derek Orr, Mar 21 2015

Formula

a(n) = a(n-2)+a(n-3)-floor(a(n-3)/2)-floor(a(n-4)/2).
Empirical g.f.: (x^3+1) / (x^6-x^5-x+1) = (x+1)*(x^2-x+1) / ((x-1)^2*(x^4+x^3+x^2+x+1)). - Colin Barker, Mar 23 2013
From Wesley Ivan Hurt, Mar 15 2015: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6).
a(n) = floor( (2n+5)/5 ). (End)

A220000 Sixty fourths of an inch in thousandths, rounded to nearest integer.

Original entry on oeis.org

16, 31, 47, 63, 78, 94, 109, 125, 141, 156, 172, 188, 203, 219, 234, 250, 266, 281, 297, 313, 328, 344, 359, 375, 391, 406, 422, 438, 453, 469, 484, 500, 516, 531, 547, 563, 578, 594, 609, 625, 641, 656, 672, 688, 703, 719, 734, 750, 766, 781
Offset: 1

Views

Author

Marc Alan Rosner, Dec 03 2012

Keywords

Comments

Diameter of successive drill bits, in thousandths of an inch, within an ordered set consisting of increments of 1/64th of an inch. Traditionally the sizes of bits in such a set are expressed in simplest reduced fractional inch values: 1/64, 1/32, 3/64, 1/16, etc. Of fundamental importance to machinists, tool and die makers, carpenters, hobbyists, insomnial science teachers, etc.

Examples

			For n = 5 the a(5) term = (5/64)*1000 = 78.125, which is rounded to 78.

References

  • Jack Erjavec, Automotive Technology, 2010, pages 66-73.
  • Frank D. Graham, Audels Machinists and Tool Makers Handy Book, 1941, pages 34-48.
  • IBM Corp., Precision Measurement in the Metal Working Industry, 1939, page 11.

Links

Crossrefs

Cf. A085269, A029919, A029920, A169860, A169861.

Programs

Formula

a(n) = round(125*n/8), with 0.5 rounded up.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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