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.

Previous Showing 11-18 of 18 results.

A121901 a(n) = floor((Pi + e)*sqrt(n)).

Original entry on oeis.org

0, 5, 8, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 21, 22, 23, 24, 24, 25, 26, 26, 27, 28, 28, 29, 29, 30, 31, 31, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37, 37, 38, 38, 39, 39, 40, 40, 41, 41, 41, 42, 42, 43, 43, 43, 44, 44, 45, 45, 45, 46, 46, 46, 47, 47, 47, 48, 48
Offset: 0

Views

Author

Mohammad K. Azarian, Sep 01 2006

Keywords

Crossrefs

Programs

  • Magma
    C := ComplexField(); [Floor((Exp(1) + Pi(C))*Sqrt(n)): n in [0..50]]; // G. C. Greubel, Oct 28 2017
  • Mathematica
    Table[Floor[(Pi + E) Sqrt[n]], {n, 0, 70}] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(floor((exp(1)+Pi)*sqrt(n)), ", ")) \\ G. C. Greubel, Oct 28 2017
    

Extensions

Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022

A121902 a(n) = floor((Pi - e)*sqrt(n)).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
Offset: 0

Author

Mohammad K. Azarian, Sep 01 2006

Keywords

Crossrefs

Programs

  • Magma
    C := ComplexField(); [Floor((Pi(C) - Exp(1))*Sqrt(n)): n in [0..50]]; // G. C. Greubel, Oct 28 2017
  • Mathematica
    Table[Floor[(Pi - E)*Sqrt[n]], {n, 0, 110}] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(floor((Pi - exp(1))*sqrt(n)), ", ")) \\ G. C. Greubel, Oct 28 2017
    

Extensions

Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022

A121903 a(n) = ceiling(Pi^(n*e)).

Original entry on oeis.org

1, 23, 505, 11329, 254434, 5714357, 128339633, 2882400038, 64736277049, 1453922256330, 32653869265130, 733378399940297, 16471061151498381, 369926160190271627, 8308229975861003526, 186595847388277259848, 4190785566084546949288, 94121513992523815815370
Offset: 0

Author

Mohammad K. Azarian, Sep 01 2006

Keywords

Crossrefs

Programs

  • Magma
    C := ComplexField(); [Ceiling(Pi(C)^(n*Exp(1))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
  • Mathematica
    Ceiling[Pi^(E Range[0, 20])] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(ceil(Pi^(n*exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
    

Extensions

Offset corrected by Georg Fischer, Aug 18 2022
Offset corrected for b-file by Sidney Cadot, Jan 06 2023

A121916 a(n) = floor((Pi+e)^(n*e)).

Original entry on oeis.org

1, 122, 14951, 1828144, 223535959, 27332807665, 3342112728281, 408656059975457, 49968325108097955, 6109865382293662597, 747082374864324679924, 91349324397617876090443, 11169717488538903806777417, 1365774619533204572560235117
Offset: 0

Author

Mohammad K. Azarian, Sep 02 2006

Keywords

Crossrefs

Programs

  • Magma
    C := ComplexField(); [Floor((Pi(C) + Exp(1))^(n*Exp(1))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
  • Mathematica
    Floor[(Pi + E)^(E (Range[0, 20]))] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(floor((Pi+exp(1))^(n*exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
    

Extensions

Offset changed to 0 by Georg Fischer, Sep 02 2022

A121918 a(n) = ceiling((Pi+e)^(n*Pi)).

Original entry on oeis.org

1, 259, 66802, 17265409, 4462406596, 1153350806022, 298094324981779, 77045272021641917, 19913072619720776033, 5146720243221262934094, 1330218081751512472685764, 343807329988307215923432747, 88860226586342124489251555257, 22966758356328845813340839281382
Offset: 0

Author

Mohammad K. Azarian, Sep 02 2006

Keywords

Programs

  • Magma
    C := ComplexField(); [Ceiling((Pi(C) + Exp(1))^(n*Pi(C))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
  • Mathematica
    With[{a = \[Pi] + E}, Ceiling[a^(\[Pi] Range[0, 20])]] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(ceil((Pi+exp(1))^(n*Pi)), ", ")) \\ G. C. Greubel, Nov 06 2017
    

Extensions

Offset changed to 0 by Georg Fischer, Sep 02 2022

A121928 a(n) = ceiling(n*(e^Pi - Pi^e)).

Original entry on oeis.org

0, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 9, 9, 10, 11, 11, 12, 13, 13, 14, 15, 15, 16, 17, 18, 18, 19, 20, 20, 21, 22, 22, 23, 24, 24, 25, 26, 26, 27, 28, 28, 29, 30, 30, 31, 32, 33, 33, 34, 35, 35, 36, 37, 37, 38, 39, 39, 40, 41, 41, 42, 43, 43, 44, 45, 45, 46, 47, 48, 48, 49, 50, 50
Offset: 0

Author

Mohammad K. Azarian, Sep 02 2006

Keywords

Programs

  • Magma
    C := ComplexField(); [Ceiling(n*(Exp(1)^Pi(C) - Pi(C)^Exp(1) )): n in [0..50]]; // G. C. Greubel, Nov 06 2017
  • Mathematica
    With[{a = E^Pi - Pi^E}, Ceiling[a Range[0, 80]]] (* Vincenzo Librandi, Feb 21 2013 *)
  • PARI
    for(n=0,50, print1(ceil(n*(exp(Pi) - Pi^exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
    

Extensions

Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022

A121925 a(n) = floor(n*(Pi^e + e^Pi)).

Original entry on oeis.org

0, 45, 91, 136, 182, 227, 273, 319, 364, 410, 455, 501, 547, 592, 638, 683, 729, 775, 820, 866, 911, 957, 1003, 1048, 1094, 1139, 1185, 1231, 1276, 1322, 1367, 1413, 1459, 1504, 1550, 1595, 1641, 1687, 1732, 1778, 1823, 1869, 1915, 1960, 2006, 2051, 2097
Offset: 0

Author

Mohammad K. Azarian, Sep 02 2006

Keywords

Crossrefs

Programs

  • Magma
    C := ComplexField(); [Floor(n*(Pi(C)^Exp(1) + Exp(1)^Pi(C))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
  • Mathematica
    With[{a = Pi^E + E^Pi}, Floor[a * Range[0, 40]]] (* Vincenzo Librandi, Feb 20 2013 *)
  • PARI
    a(n)=floor(n*(Pi^exp(1)+exp(Pi))) \\ Charles R Greathouse IV, Feb 20 2013
    

Extensions

Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022

A332045 Numbers k such that ceiling(Pi/arctan(1/k)) = ceiling(k*Pi)+1.

Original entry on oeis.org

6, 7, 14, 21, 28, 113, 226, 339, 452, 565, 678, 791, 904, 1017, 1130, 1243, 1356, 1469, 1582, 1695, 1808, 1921, 33215, 99532, 364913, 729826, 1725033, 3450066, 5175099, 27235615, 52746197, 131002976, 471265707, 811528438, 2774848045, 4738167652, 567663097408
Offset: 1

Author

Jianing Song, Feb 05 2020

Keywords

Comments

Note that ceiling(Pi/arctan(1/k)) - ceiling(k*Pi) is equal to either 0 or 1, that is, for all other k we have ceiling(Pi/arctan(1/k)) = ceiling(k*Pi).
Numbers k such that there exists some integer m such that Pi/arctan(1/k) > m > k*Pi.
Numbers k such that A331859(k^2) = A121854(k^2)+1 = A121855(k^2).
In A331859 there is a remark that A331859(100^n) = A011545(n). I'm in doubt of this, because if k = 10^n is here, then A331859(100^n) = ceiling(k*Pi), while A011545(n) = ceiling(k*Pi)-1, this equality would be violated.
Note that for k >= 3 we have 1/k < Pi/arctan(1/k)-k*Pi < (Pi/3)/k. As a result, a necessary condition for k being a term here is that there exists some m such that 0 < m/k - Pi < (Pi/3)/k^2, and a sufficient condition is that there exists some m such that 0 < m/k - Pi < 1/k^2.
Let P(n) = A002485(n), Q(n) = A002486(n), then it is known that 1/(Q(n)*(Q(n)*Q(n+1))) < |P(n)/Q(n) - Pi| < 1/(Q(n)*Q(n+1)) for n >= 2; furthermore, P(n)/Q(n) - Pi is positive for odd n and negative for even n. As a result, let n >= 3, then we have:
- If n is even, then Q(n) can never be a term.
- If n is odd, then k = Q(n)*t is a term if t <= sqrt(Q(n+1)/Q(n)), in which case ceiling(Pi/arctan(1/k)) = P(n)*t+1 and ceiling(k*Pi) = P(n)*t. The converse is not true (e.g., n = 3, t = 4745).

Examples

			Pi/arctan(1/6) = 19.0228..., 6*Pi = 18.8495..., so 6 is a term.
113*t is here for t <= 17, because ceiling(Pi/arctan(1/(113*t))) = 355*t+1 and ceiling((113*t)*Pi) = 355*t.
		

Crossrefs

Cf. A121381 (ceiling(n*Pi)), A121854 (floor(sqrt(n)*Pi)), A121855 (ceiling(sqrt(n)*Pi)), A011545 (floor(10^n*Pi)).

Programs

  • Magma
    // See Schoenfield link.
  • PARI
    default(realprecision, 10000); isA332045(n) = ceil(Pi/atan(1/n))!=ceil(n*Pi)
    

Extensions

a(27)-a(32) from Jon E. Schoenfield, Feb 12 2020
a(33)-a(36) from Giovanni Resta, Feb 12 2020
a(37) from Jon E. Schoenfield, Feb 15 2020
Previous Showing 11-18 of 18 results.