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 1-10 of 10 results.

A103208 Numbers k such that 3 divides prime(1) + ... + prime(k).

Original entry on oeis.org

10, 16, 18, 20, 24, 26, 28, 30, 32, 34, 36, 40, 42, 44, 46, 52, 54, 57, 68, 70, 74, 76, 78, 80, 82, 84, 86, 88, 90, 97, 99, 103, 105, 107, 111, 113, 119, 121, 123, 125, 127, 129, 134, 136, 138, 161, 163, 166, 169, 175, 177, 179, 185, 187, 195, 197, 199, 203, 205, 207, 211, 213
Offset: 1

Views

Author

Robert G. Wilson v, Mar 19 2005

Keywords

Comments

Also, numbers k such that 3 divides the concatenation of the first k primes (see A019518).
The first comment and the description are true whenever the number of primes congruent to 1 mod 6 exceeds the number of primes congruent to 5 mod 6 and the difference is congruent to 1 mod 3 or the number of primes congruent to 5 mod 6 exceeds the number of primes congruent to 1 mod 6 and the difference is congruent to 2 mod 3. - Roderick MacPhee, Oct 30 2015

Crossrefs

Programs

  • Maple
    s1:=[2]; M:=1000; for n from 2 to M do s1:=[op(s1),s1[n-1]+ithprime(n)]; od: s1;
    f:=proc(k) global M,s1; local t1,n; t1:=[]; for n from 1 to M do if s1[n] mod k = 0 then t1:=[op(t1),n]; fi; od: t1; end; f(3);
  • Mathematica
    f[n_] := FromDigits[ Flatten[ Table[ IntegerDigits[ Prime[i]], {i, n}]]]; Select[ Range[ 206], Mod[f[ # ], 3] == 0 &]
    Flatten[Position[Accumulate[Prime[Range[250]]],?(Divisible[#,3]&)]] (* _Harvey P. Dale, Jan 14 2016 *)
  • PARI
    a=0;b=0;for(x=3,1000,if(prime(x)%6==1,a+=1,b+=1);if((a-b)%3==1 || (b-a)%3==2,print1(x","))) \\ Roderick MacPhee, Oct 30 2015
    
  • PARI
    lista(nn) = { s=0; for(k=1, nn, s += prime(k); if(s % 3 == 0, print1(k, ", ")););} \\ Altug Alkan, Dec 04 2015

Extensions

Entry revised by N. J. A. Sloane, Nov 09 2005

A111319 Numbers k such that 5 divides prime(1) + ... + prime(k).

Original entry on oeis.org

2, 3, 9, 11, 17, 25, 29, 31, 51, 53, 57, 62, 71, 77, 85, 89, 91, 101, 103, 105, 116, 118, 131, 147, 153, 156, 159, 167, 173, 180, 186, 188, 190, 195, 209, 226, 230, 239, 242, 245, 256, 259, 261, 266, 268, 283, 292, 298, 303, 314, 317, 324, 349, 352, 357, 364, 366, 368, 376
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

A111320 Numbers k such that 6 divides prime(1) + ... + prime(k).

Original entry on oeis.org

57, 97, 99, 103, 105, 107, 111, 113, 119, 121, 123, 125, 127, 129, 161, 163, 169, 175, 177, 179, 185, 187, 195, 197, 199, 203, 205, 207, 211, 213, 217, 233, 235, 237, 273, 293, 295, 297, 301, 303, 305, 307, 309, 311, 327, 329, 331, 333, 335, 337, 339, 343, 345, 347, 349
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Comments

Odd terms in A103208. - Robert Israel, Jan 26 2019

Crossrefs

Programs

  • Maple
    P:= [seq(ithprime(i),i=1..1000)]:
    L:= ListTools:-PartialSums(P):
    select(t -> L[t] mod 6 = 0, [seq(i,i=1..1000)]); # Robert Israel, Jan 26 2019
  • Mathematica
    Position[Accumulate[Prime[Range[400]]], ?(Divisible[#, 6] &)] // Flatten (* _Amiram Eldar, May 14 2024 *)
  • PARI
    lista(pmax) = {my(s = 0, k = 0); forprime(p = 2, pmax, k++; s += p; if(!(s % 6), print1(k, ", ")));} \\ Amiram Eldar, May 14 2024

A111324 Numbers k such that 10 divides prime(1) + ... + prime(k).

Original entry on oeis.org

3, 9, 11, 17, 25, 29, 31, 51, 53, 57, 71, 77, 85, 89, 91, 101, 103, 105, 131, 147, 153, 159, 167, 173, 195, 209, 239, 245, 259, 261, 283, 303, 317, 349, 357, 405, 453, 459, 475, 479, 491, 503, 505, 507, 511, 517, 531, 533, 545, 555, 565, 569, 583, 585, 591, 603, 617, 625
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

A111318 Numbers k such that 4 divides prime(1) + ... + prime(k).

Original entry on oeis.org

5, 9, 11, 15, 17, 19, 21, 25, 27, 29, 31, 33, 35, 37, 45, 49, 71, 79, 81, 83, 85, 87, 91, 95, 97, 99, 101, 103, 105, 107, 109, 111, 115, 117, 119, 121, 125, 129, 131, 135, 155, 159, 161, 163, 165, 169, 171, 173, 175, 177, 179, 181, 183, 185, 193, 195, 199, 201, 203, 205
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Module[{nn=300,prs},prs=Accumulate[Prime[Range[nn]]];Select[Range[ nn], Divisible[prs[[#]],4]&]] (* Harvey P. Dale, May 27 2012 *)
  • PARI
    lista(pmax) = {my(s = 0, k = 0); forprime(p = 2, pmax, k++; s += p; if(!(s % 4), print1(k, ", ")));} \\ Amiram Eldar, May 14 2024

A111321 Numbers k such that 7 divides prime(1) + ... + prime(k).

Original entry on oeis.org

5, 8, 13, 22, 33, 40, 47, 50, 56, 63, 72, 84, 86, 104, 106, 110, 115, 126, 128, 139, 148, 150, 154, 157, 160, 180, 184, 186, 188, 200, 209, 220, 228, 230, 232, 236, 238, 240, 244, 253, 270, 274, 300, 302, 305, 322, 324, 331, 339, 354, 367, 371, 384, 415, 417, 420, 428, 433
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

A111322 Numbers k such that 8 divides prime(1) + ... + prime(k).

Original entry on oeis.org

11, 15, 17, 19, 21, 27, 29, 31, 37, 49, 71, 79, 83, 85, 95, 99, 101, 103, 107, 109, 111, 115, 119, 121, 135, 155, 159, 161, 163, 169, 171, 177, 181, 183, 185, 201, 205, 209, 213, 235, 237, 239, 247, 255, 257, 259, 261, 263, 273, 275, 279, 283, 285, 287, 305, 309, 317, 319
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

A111323 Numbers k such that 9 divides prime(1) + ... + prime(k).

Original entry on oeis.org

20, 24, 26, 30, 40, 42, 52, 74, 78, 80, 88, 113, 119, 127, 163, 177, 179, 187, 205, 207, 242, 248, 254, 258, 260, 262, 268, 270, 280, 282, 284, 288, 297, 311, 331, 357, 368, 372, 380, 394, 398, 400, 410, 412, 416, 428, 436, 443, 457, 466, 468, 470, 474, 490, 496, 505, 509
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Flatten[Position[Accumulate[Prime[Range[509]]]/9,Integer]] (* _Jayanta Basu, May 18 2013 *)
  • PARI
    lista(pmax) = {my(s = 0, k = 0); forprime(p = 2, pmax, k++; s += p; if(!(s % 9), print1(k, ", ")));} \\ Amiram Eldar, May 14 2024

A111325 Numbers k such that 11 divides prime(1) + ... + prime(k).

Original entry on oeis.org

8, 17, 53, 69, 76, 84, 87, 91, 167, 175, 179, 181, 188, 196, 201, 217, 219, 224, 240, 260, 275, 297, 312, 317, 319, 324, 340, 346, 376, 382, 386, 393, 417, 470, 503, 514, 526, 528, 542, 550, 562, 564, 584, 590, 607, 613, 615, 629, 637, 649, 691, 693, 732, 749, 752, 759
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Position[Accumulate[Prime[Range[400]]], ?(Divisible[#, 11] &)] // Flatten (* _Amiram Eldar, May 14 2024 *)
  • PARI
    lista(pmax) = {my(s = 0, k = 0); forprime(p = 2, pmax, k++; s += p; if(!(s % 11), print1(k, ", ")));} \\ Amiram Eldar, May 14 2024
  • Python
    from sympy import nextprime
    def aupto(limit):
        p, s, alst = 2, 2, []
        for k in range(1, limit+1):
            if s == 0: alst.append(k)
            p = nextprime(p); s = (s + p)%11
        return alst
    print(aupto(759)) # Michael S. Branicky, Aug 17 2021
    

A111326 Numbers k such that 12 divides prime(1) + ... + prime(k).

Original entry on oeis.org

97, 99, 103, 105, 107, 111, 119, 121, 125, 129, 161, 163, 169, 175, 177, 179, 185, 195, 199, 203, 205, 207, 211, 213, 233, 235, 237, 273, 305, 307, 309, 311, 329, 335, 337, 343, 345, 347, 353, 357, 421, 423, 425, 439, 443, 445, 447, 449, 455, 463, 511, 513, 515, 539
Offset: 1

Views

Author

N. J. A. Sloane, Nov 05 2005

Keywords

Crossrefs

Programs

Showing 1-10 of 10 results.