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.

A263769 Smallest prime q such that q == -1 (mod prime(n)-1).

Original entry on oeis.org

2, 3, 3, 5, 19, 11, 31, 17, 43, 83, 29, 71, 79, 41, 137, 103, 173, 59, 131, 139, 71, 233, 163, 263, 191, 199, 101, 211, 107, 223, 251, 389, 271, 137, 443, 149, 311, 647, 331, 859, 1423, 179, 379, 191, 587, 197, 419, 443
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Oct 25 2015

Keywords

Comments

a(n): A000040(1), A065091(1), A002145(1), A007528(1), A030433(1), A068231(1), A127576(1), A061242(1), A141857(1), A141976(1), A132236(1), A142111(1), A142198(1), A141898(1), A141926(1), A142531(1), A142004(1), A142799(1), A142068(1), A142099(1), ...
Smallest prime q such that (prime(n)^2 + q*prime(n))/(prime(n) + 1) is an integer.

Examples

			a(4) = 5 because 5 == -1 (mod prime(4)-1) and is prime.
		

Crossrefs

Programs

  • Maple
    for n from 1 to 100 do
      k:= ithprime(n)-1;
      q:= 2;
      while (1 + q) mod k <> 0 do
        q:= nextprime(q)
      od;
      A[n]:= q;
    od:
    seq(A[i],i=1..1000); # Robert Israel, Oct 26 2015
  • Mathematica
    Table[q = 2; z = Prime@ n - 1; While[Mod[q, z] != z - 1, q = NextPrime@ q]; q, {n, 59}] (* Michael De Vlieger, Oct 26 2015 *)

Extensions

Corrected and edited by Robert Israel, Oct 26 2015,

A142066 Primes congruent to 29 mod 33.

Original entry on oeis.org

29, 227, 293, 359, 491, 557, 821, 887, 953, 1019, 1151, 1217, 1283, 1481, 1613, 1811, 1877, 2141, 2207, 2273, 2339, 2801, 2999, 3329, 3461, 3527, 3593, 3659, 3923, 3989, 4253, 4451, 4517, 4583, 4649, 5309, 5441, 5507, 5573, 5639, 5903, 6101, 6299, 6563
Offset: 1

Views

Author

N. J. A. Sloane, Jul 11 2008

Keywords

Crossrefs

Programs

Formula

a(n) ~ 20n log n. - Charles R Greathouse IV, Jul 03 2016

A161505 Primes congruent to {1, 7, 8, 25, 26, 32} mod 33.

Original entry on oeis.org

7, 41, 59, 67, 73, 107, 131, 139, 157, 173, 191, 197, 199, 223, 239, 257, 263, 271, 331, 337, 389, 397, 421, 461, 463, 487, 503, 521, 569, 587, 593, 601, 619, 653, 659, 661, 701, 719, 727, 733, 751, 857, 859, 883, 983, 991, 997, 1031, 1049, 1063, 1097, 1123
Offset: 1

Views

Author

T. D. Noe, Jun 17 2009

Keywords

Comments

The cyclotomic polynomial Phi(33p,x) is flat only for p in this sequence.

Crossrefs

Programs

  • Mathematica
    Flatten[Table[Select[33*n+{-8,-7,-1,1,7,8}, PrimeQ], {n,50}]]

Formula

Extensions

a(1)=7 inserted by Georg Fischer, Jul 26 2020

A301619 Primes congruent to 65 (mod 192).

Original entry on oeis.org

257, 449, 641, 1217, 1409, 1601, 2753, 3137, 3329, 4289, 4481, 4673, 5441, 6977, 7937, 8513, 9281, 9473, 9857, 10433, 11393, 11777, 11969, 12161, 13121, 13313, 13697, 14081, 14657, 15233, 15809, 16001, 16193, 17729, 17921, 19073, 19457, 19841, 21377, 21569
Offset: 1

Views

Author

Felix Fröhlich, Mar 24 2018

Keywords

Comments

In other words, primes of the form 192*k+65 for k > 0.

Crossrefs

Subsequence of A002144 (primes of form 4*k+65) and A007519 (primes of form 8*k+65).
Cf. primes congruent to 65 (mod k): A142068 (k=66), A142137 (k=74), A142221 (k=82), A142271 (k=86), A142369 (k=94), A142427 (k=98), A142485 (k=102), A142542 (k=106), A142670 (k=114), A142733 (k=118), A142802 (k=122), A142890 (k=126), A105129 (k=128).

Programs

  • Magma
    [p: p in PrimesUpTo(25000) | p mod 192 in {65}]; // Vincenzo Librandi, Jan 04 2020
  • Mathematica
    Select[Prime[Range[2500]], MemberQ[{65}, Mod[#, 192]] &] (* Vincenzo Librandi, Jan 04 2020 *)
  • PARI
    forprime(p=1, 5e4, if(Mod(p, 192)==65, print1(p, ", ")))
    
Showing 1-4 of 4 results.