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 1-8 of 8 results.

A094407 Primes of the form 16n+1.

Original entry on oeis.org

17, 97, 113, 193, 241, 257, 337, 353, 401, 433, 449, 577, 593, 641, 673, 769, 881, 929, 977, 1009, 1153, 1201, 1217, 1249, 1297, 1361, 1409, 1489, 1553, 1601, 1697, 1777, 1873, 1889, 2017, 2081, 2113, 2129, 2161, 2273, 2417, 2593, 2609, 2657, 2689, 2753
Offset: 1

Views

Author

Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Jun 03 2004

Keywords

Comments

Subsequence of A007519 (primes of form 8n+1). - Zak Seidov, May 16 2012
Primes p such that p XOR 14 = p + 14. - Brad Clardy, Jul 23 2012
A prime of the form 16n+1 is represented either by both x^2+32y^2 and x^2+64y^2 or by neither (see Kaplansky link). - Michel Marcus, Dec 23 2012
Odd primes p such that -1 is an 8th power mod p. - Eric M. Schmidt, Mar 27 2014

Crossrefs

Programs

  • Haskell
    a094407 n = a094407_list !! (n-1)
    a094407_list = filter ((== 1) . a010051) [1,17..]
    -- Reinhard Zumkeller, Mar 06 2012
  • Maple
    p:=proc(n) if isprime(16*n+1)=true then 16*n+1 else fi end:seq(p(n),n=1..200); # Emeric Deutsch, Dec 23 2004
  • Mathematica
    lst={};Do[p=16*n+1;If[PrimeQ[p],AppendTo[lst,p]],{n,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Feb 26 2009 *)
    Select[16*Range[200]+1,PrimeQ] (* Harvey P. Dale, Nov 04 2017 *)

Extensions

More terms from Emeric Deutsch, Dec 23 2004

A092022 Numbers k such that 16k + 3 is prime.

Original entry on oeis.org

0, 1, 4, 5, 8, 10, 11, 13, 14, 19, 26, 29, 31, 34, 35, 40, 41, 43, 46, 49, 55, 59, 68, 70, 73, 74, 80, 89, 91, 95, 98, 101, 104, 106, 109, 113, 119, 124, 125, 130, 131, 133, 136, 140, 146, 148, 154, 158, 161, 166, 169, 175, 176, 178, 185, 188, 199, 200, 203, 206, 208
Offset: 1

Views

Author

Ray Chandler, Mar 15 2004

Keywords

Crossrefs

Programs

Formula

a(n) = (A091968(n)-3)/16. - Zak Seidov, Mar 28 2015

A141194 Primes of the form 16k+7.

Original entry on oeis.org

7, 23, 71, 103, 151, 167, 199, 263, 311, 359, 439, 487, 503, 599, 631, 647, 727, 743, 823, 839, 887, 919, 967, 983, 1031, 1063, 1223, 1303, 1319, 1367, 1399, 1447, 1511, 1543, 1559, 1607, 1783, 1831, 1847, 1879, 2039, 2087, 2311, 2423, 2503, 2551, 2647
Offset: 1

Views

Author

T. D. Noe, Jun 12 2008

Keywords

Crossrefs

Programs

A141195 Primes of the form 16k+11.

Original entry on oeis.org

11, 43, 59, 107, 139, 251, 283, 331, 347, 379, 443, 491, 523, 571, 587, 619, 683, 811, 827, 859, 907, 971, 1019, 1051, 1163, 1259, 1291, 1307, 1451, 1483, 1499, 1531, 1579, 1627, 1723, 1787, 1867, 1931, 1979, 2011, 2027, 2203, 2251, 2267, 2347, 2411, 2459
Offset: 1

Views

Author

T. D. Noe, Jun 12 2008

Keywords

Crossrefs

Programs

A141196 Primes of the form 16k+13.

Original entry on oeis.org

13, 29, 61, 109, 157, 173, 269, 317, 349, 397, 461, 509, 541, 557, 653, 701, 733, 797, 829, 877, 941, 1021, 1069, 1117, 1181, 1213, 1229, 1277, 1373, 1453, 1549, 1597, 1613, 1693, 1709, 1741, 1789, 1901, 1933, 1949, 1997, 2029, 2141, 2221, 2237, 2269
Offset: 1

Views

Author

T. D. Noe, Jun 12 2008

Keywords

Comments

Which sequence, this or A141194, produces more primes? The race is very close. For example, A141194(1000)=80599 and A141196(1000)=80909, a difference of just 32 primes after a thousand terms. - Art Baker, Aug 07 2019

Crossrefs

Programs

A093012 Numbers k such that prime(k) == 3 (mod 16).

Original entry on oeis.org

2, 8, 19, 23, 32, 38, 41, 47, 49, 63, 81, 91, 95, 101, 103, 117, 120, 125, 131, 138, 153, 161, 182, 188, 193, 195, 208, 225, 232, 241, 248, 256, 262, 266, 272, 280, 292, 300, 304, 314, 317, 321, 327, 334, 346, 351, 365, 370, 376, 385, 394, 409, 410, 414, 427
Offset: 1

Views

Author

Ray Chandler, Mar 15 2004, revised Nov 06 2006

Keywords

Comments

A091968 indexed by A000040.
The asymptotic density of this sequence is 1/8 (by Dirichlet's theorem). - Amiram Eldar, Mar 01 2021

Crossrefs

Programs

  • Magma
    [n: n in [1..450]|(NthPrime(n) mod 16) eq 3] // G. C. Greubel, Feb 05 2019
    
  • Mathematica
    Select[Range[430], Mod[Prime[ # ], 16] == 3 &] (* Ray Chandler, Nov 06 2006 *)
  • PARI
    {isok(n) = Mod(prime(n), 16)==3};
    for(n=1, 450, if(isok(n)==1, print1(n, ", "), 0)) \\ G. C. Greubel, Feb 05 2019

Formula

A000040(a(n)) = A091968(n).
a(n) = A000720(A091968(n)).

A228228 Primes congruent to {3, 5, 13, 15} mod 16.

Original entry on oeis.org

3, 5, 13, 19, 29, 31, 37, 47, 53, 61, 67, 79, 83, 101, 109, 127, 131, 149, 157, 163, 173, 179, 181, 191, 197, 211, 223, 227, 229, 239, 269, 271, 277, 293, 307, 317, 349, 367, 373, 383, 389, 397, 419, 421, 431, 461, 463, 467, 479, 499, 509, 541, 547, 557, 563
Offset: 1

Views

Author

Arkadiusz Wesolowski, Aug 16 2013

Keywords

Comments

Union of A091968, A127589, A141196, and A127576.
Let p be a prime number and let E(p) denote the elliptic curve y^2 = x^3 + p*x. If p is in the sequence, then the rank of E(p) is 0 or 1. Therefore, A060953(a(n)) must be one of only two values: 0 or 1.

References

  • J. H. Silverman, The arithmetic of elliptic curves, Springer, NY, 1986, p. 311.

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(563) | p mod 16 in {3, 5, 13, 15}];
  • Mathematica
    Select[Prime@Range[103], MemberQ[{3, 5, 13, 15}, Mod[#, 16]] &]

A321212 Numbers that are congruent to {2, 3} mod 16.

Original entry on oeis.org

2, 3, 18, 19, 34, 35, 50, 51, 66, 67, 82, 83, 98, 99, 114, 115, 130, 131, 146, 147, 162, 163, 178, 179, 194, 195, 210, 211, 226, 227, 242, 243, 258, 259, 274, 275, 290, 291, 306, 307, 322, 323, 338, 339, 354, 355, 370, 371, 386, 387, 402, 403, 418, 419, 434, 435, 450, 451, 466, 467, 482, 483, 498, 499
Offset: 1

Views

Author

Yuen Biu, Oct 31 2018

Keywords

Crossrefs

A091968 is a subsequence.

Programs

  • Magma
    [n: n in [1..500] | n mod 16 in [2, 3]]; // Vincenzo Librandi, Nov 30 2018
    
  • Mathematica
    Flatten@ Array[16 # + {2, 3} &, 31, 0] (* Michael De Vlieger, Oct 31 2018 *)
    Select[Range[1, 500], MemberQ[{2,3}, Mod[#, 16]] &] (* Vincenzo Librandi, Nov 30 2018 *)
  • PARI
    a(n) = (16*n - 7*(-1)^n - 19)/2 \\ David Lovler, Aug 20 2022

Formula

a(n) = A151977(n) + 2.
G.f.: x*(2 + x + 13*x^2)/((-1 + x)^2*(1 + x)). - Stefano Spezia, Nov 01 2018
a(n) = a(n-1) + a(n-2) - a(n-3) for n > 3. - Chai Wah Wu, Nov 29 2018
From Franck Maminirina Ramaharo, Nov 30 2018: (Start)
a(n) = (16*n - 7*(-1)^n - 19)/2.
E.g.f.: (-7 + 26*exp(x) - 19*exp(2*x) + 16*x*exp(2*x))/(2*exp(x)). (End)
E.g.f.: 13 + ((16*x -19)*exp(x) - 7*exp(-x))/2. - David Lovler, Aug 20 2022
a(n) = a(n-2) + 16. - David A. Corneth, Nov 30 2018
Showing 1-8 of 8 results.