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.

A184855 Numbers m such that prime(m) is of the form (k*e); complement of A184858.

Original entry on oeis.org

1, 3, 6, 8, 10, 14, 17, 19, 21, 24, 25, 27, 31, 35, 37, 38, 40, 41, 51, 52, 53, 56, 57, 58, 59, 62, 63, 67, 68, 69, 71, 76, 82, 86, 91, 98, 102, 107, 113, 114, 116, 126, 127, 130, 131, 135, 136, 143, 145, 146, 147, 153, 155, 158, 159, 163, 168, 170, 171, 176, 177, 181, 185, 186, 187, 192, 193, 195, 196, 197, 199, 200, 202, 206, 208, 210, 214, 216, 218, 219, 222, 225, 226, 230, 232, 234, 237, 240, 243, 244, 248, 249, 252, 254
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Examples

			See A077545.
		

Crossrefs

Programs

  • Mathematica
    r=E; s=r/(r-1);
    a[n_]:=Floor [n*r];
    b[n_]:=Floor [n*s];
    Table[a[n], {n, 1, 120}]  (* A022843 *)
    t1={}; Do[If[PrimeQ[a[n]], AppendTo[t1, a[n]]], {n, 1, 600}]; t1
    t2={}; Do[If[PrimeQ[a[n]], AppendTo[t2, n]], {n, 1, 600}]; t2
    t3={}; Do[If[MemberQ[t1, Prime[n]], AppendTo[t3, n]], {n, 1, 300}]; t3
    t4={}; Do[If[PrimeQ[b[n]], AppendTo[t4, b[n]]], {n, 1, 600}]; t4
    t5={}; Do[If[PrimeQ[b[n]], AppendTo[t5, n]], {n, 1, 600}]; t5
    t6={}; Do[If[MemberQ[t4, Prime[n]], AppendTo[t6, n]], {n, 1, 300}]; t6
    (* List t1 matches A077545; list t2 matches A062409;
    lists t3-t6 match A184855-A184858. *)

A062409 Numbers k such that floor(e*k) is prime.

Original entry on oeis.org

1, 2, 5, 7, 11, 16, 22, 25, 27, 33, 36, 38, 47, 55, 58, 60, 64, 66, 86, 88, 89, 97, 99, 100, 102, 108, 113, 122, 124, 128, 130, 141, 155, 163, 172, 192, 205, 216, 227, 228, 236, 258, 261, 270, 272, 280, 283, 303, 305, 309, 314, 325, 334, 342, 345, 356, 367, 373
Offset: 1

Views

Author

Jason Earls, Jul 08 2001

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Range[400],PrimeQ[Floor[E #]]&] (* Harvey P. Dale, Feb 12 2015 *)
  • PARI
    je=[]; for(n=0,1000, if(isprime(floor(exp(1)*n)),je=concat(je,n),)); je
    
  • PARI
    { default(realprecision, 50); n=0; e=exp(1); for (m=1, 10^5, if (isprime(floor(e*m)), write("b062409.txt", n++, " ", m); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 07 2009

A184856 Primes of the form floor(k*e/(e-1)).

Original entry on oeis.org

3, 7, 11, 17, 23, 31, 37, 41, 47, 53, 61, 71, 79, 83, 101, 107, 109, 113, 131, 137, 139, 151, 167, 181, 191, 193, 197, 199, 211, 223, 227, 229, 251, 257, 281, 283, 311, 313, 317, 349, 359, 367, 373, 379, 389, 397, 401, 409, 419, 431, 433, 439, 449, 457, 461, 463, 479, 487, 491, 499, 503, 509, 523, 541, 547, 563, 569, 571, 577, 593, 599, 601, 607, 613, 631, 643, 647, 653, 659, 661, 673, 677, 683, 691, 719, 727, 743, 751, 757, 773, 787, 797, 809, 811, 821, 827, 857, 859, 863, 877, 881, 887, 911, 919, 941, 947
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Comments

Primes in A054385. - Bill McEachen, Nov 04 2021

Examples

			See A077545.
		

Crossrefs

Programs

  • Mathematica
    (See A077545.)
  • PARI
    select( {is_A184856(n, c=1-exp(-1)) = isprime(n) && for(k=floor(n*c),ceil((n+1)*c), k\c==n && return(1))}, [1..999]) \\ M. F. Hasler, Jul 12 2024

Formula

Complement of A077545 in the primes: A000040 \ A077545. - M. F. Hasler, Jul 12 2024

A184858 Numbers m such that prime(m) is of the form floor(k*e/(e-1)); complement of A184855.

Original entry on oeis.org

2, 4, 5, 7, 9, 11, 12, 13, 15, 16, 18, 20, 22, 23, 26, 28, 29, 30, 32, 33, 34, 36, 39, 42, 43, 44, 45, 46, 47, 48, 49, 50, 54, 55, 60, 61, 64, 65, 66, 70, 72, 73, 74, 75, 77, 78, 79, 80, 81, 83, 84, 85, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 99, 100, 101, 103, 104, 105, 106, 108, 109, 110, 111, 112, 115, 117, 118, 119, 120, 121, 122, 123, 124, 125, 128, 129, 132, 133, 134, 137, 138, 139, 140, 141, 142, 144, 148, 149, 150, 151, 152, 154, 156, 157, 160, 161
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Examples

			See A077545.
		

Crossrefs

Programs

  • Mathematica
    PrimePi[Select[Floor[Range[1000] E/(E-1)], PrimeQ]]

A184857 Numbers k such that floor(k*e/(e-1)) is prime.

Original entry on oeis.org

2, 5, 7, 11, 15, 20, 24, 26, 30, 34, 39, 45, 50, 53, 64, 68, 69, 72, 83, 87, 88, 96, 106, 115, 121, 122, 125, 126, 134, 141, 144, 145, 159, 163, 178, 179, 197, 198, 201, 221, 227, 232, 236, 240, 246, 251, 254, 259, 265, 273, 274, 278, 284, 289, 292, 293, 303, 308, 311, 316, 318, 322, 331, 342, 346, 356, 360, 361, 365, 375, 379, 380, 384, 388, 399, 407, 409, 413, 417, 418, 426, 428, 432, 437, 455, 460, 470, 475, 479, 489, 498, 504, 512, 513, 519, 523, 542, 543, 546, 555, 557, 561, 576, 581, 595, 599
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Examples

			See A077545.
		

Crossrefs

Programs

  • Mathematica
    (See A077545.)
    Select[Range[600],PrimeQ[Floor[# E/(E-1)]]&]  (* Harvey P. Dale, Jan 25 2011 *)
Showing 1-5 of 5 results.