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 11-14 of 14 results.

A173178 Numbers k such that 2*k+3 is a prime of the form 3*A024893(m) + 2.

Original entry on oeis.org

1, 4, 7, 10, 13, 19, 22, 25, 28, 34, 40, 43, 49, 52, 55, 64, 67, 73, 82, 85, 88, 94, 97, 112, 115, 118, 124, 127, 130, 133, 139, 145, 154, 157, 172, 175, 178, 190, 193, 199, 208, 214, 220, 223, 229, 232, 238, 244, 250, 253, 259, 277, 280, 283, 292, 295, 298, 307, 319
Offset: 1

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Author

Eric Desbiaux, Feb 11 2010

Keywords

Comments

With the Bachet-Bézout theorem implicating Gauss Lemma and the Fundamental Theorem of Arithmetic,
for k > 1, k = 2*a + 3*b (a and b integers)
first type
A001477 = (2*A080425) + (3*A008611)
A000040 = (2*A039701) + (3*A157966)
A024893 Numbers k such that 3*k + 2 is prime
A034936 Numbers k such that 3*k + 4 is prime
OR second type
A001477 = (2*A028242) + (3*A059841)
A000040 = (2*A067076) + (3*1)
A067076 Numbers k such that 2*k + 3 is prime
k a b OR a b
-- - - - -
0 0 0 0 0
1 - - - -
2 1 0 1 0
3 0 1 0 1
4 2 0 2 0
5 1 1 1 1
6 0 2 3 0
7 2 1 2 1
8 1 2 4 0
9 0 3 3 1
10 2 2 5 0
11 1 3 4 1
12 0 4 6 0
13 2 3 5 1
14 1 4 7 0
15 0 5 6 1
...
2* 1 + 3 OR 3* 1 + 2 = 5;
2* 4 + 3 OR 3* 3 + 2 = 11;
2* 7 + 3 OR 3* 5 + 2 = 17;
2*10 + 3 OR 3* 7 + 2 = 23;
2*13 + 3 OR 3* 9 + 2 = 29;
2*19 + 3 OR 3*13 + 2 = 41;
2*22 + 3 OR 3*15 + 2 = 47;
2*25 + 3 OR 3*17 + 2 = 53;
2*28 + 3 OR 3*19 + 2 = 59.
A024893 Numbers k such that 3k+2 is prime.
A007528 Primes of the form 6k-1.
A024898 Positive integers k such that 6k-1 is prime.
1, 4, 7, 10, 13, 19, ... = (3*(4*A024898 - A024893) - 7)/2 = (A112774 - 3*A024893 - 5)/2 = A003627 - (3*A024893 - 5)/2.

Crossrefs

Programs

  • Mathematica
    Select[Range[0, 320], PrimeQ[(p = 2*# + 3)] && Mod[p, 3] == 2 &] (* Amiram Eldar, Jul 30 2024 *)

Formula

a(n) = 3*A059325(n) + 1. - Amiram Eldar, Jul 30 2024

Extensions

Data corrected and extended by Amiram Eldar, Jul 30 2024

A023336 Primes that remain prime through 5 iterations of function f(x) = 3x + 4.

Original entry on oeis.org

34613, 165443, 321053, 363403, 474143, 496333, 528673, 631853, 834503, 957563, 1199623, 1274803, 1817093, 1918733, 2063423, 2611663, 2889703, 3224233, 3652703, 3697433, 3824413, 3852973, 4655873, 4708793, 5089943, 5508263, 5937853, 6067073
Offset: 1

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Author

Keywords

Comments

Primes p such that 3*p+4, 9*p+16, 27*p+52, 81*p+160 and 243*p+484 are also primes. - Vincenzo Librandi, Aug 05 2010

Crossrefs

Subsequence of A023209, A023247, A023278, A023308, and A034936.

Programs

  • Magma
    [n: n in [1..25000000] | IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160) and IsPrime(243*n+484)] // Vincenzo Librandi, Aug 05 2010

Formula

a(n) == 33 (mod 70). - John Cerkan, Oct 10 2016

A124855 Numbers k such that 3k + 4 and 4k + 3 are primes.

Original entry on oeis.org

1, 5, 11, 19, 25, 31, 41, 49, 59, 65, 89, 91, 109, 115, 121, 125, 151, 161, 179, 181, 205, 209, 229, 241, 245, 275, 305, 329, 331, 349, 355, 361, 371, 389, 415, 439, 509, 515, 521, 535, 551, 595, 599, 625, 661, 665, 671, 719, 725, 749, 755, 769, 779, 791, 839
Offset: 1

Views

Author

Zak Seidov, Nov 10 2006

Keywords

Crossrefs

Intersection of A034936 and A095278. Prime terms are in A106068.

Programs

  • Magma
    [n: n in [0..1000] | IsPrime(3*n+4) and IsPrime(4*n+3)] // Vincenzo Librandi, Mar 26 2010
  • Mathematica
    Select[Range[850], PrimeQ[3# + 4] && PrimeQ[4# + 3] &] (* Ray Chandler, May 11 2007 *)

A154618 Triangle read by rows: integer values of T(n,m) = (4*m*n+2*m+2*n-3)/3.

Original entry on oeis.org

7, 15, 17, 39, 29, 55, 27, 61, 95, 43, 81, 119, 37, 83, 129, 175, 57, 107, 157, 207, 47, 105, 163, 221, 279, 71, 133, 195, 257, 319, 57, 127, 197, 267, 337, 407, 85, 159, 233, 307, 381, 455, 67, 149, 231, 313, 395, 477, 559, 99, 185, 271, 357, 443, 529, 615, 77
Offset: 1

Views

Author

Vincenzo Librandi, Jan 16 2009

Keywords

Examples

			The sequence contains the integers selected from the full table:
5/3;
11/3,7;
17/3,31/3,15;
23/3,41/3,59/3,77/3;
29/3,17,73/3,95/3,39;
35/3,61/3,29,113/3,139/3,55;
41/3,71/3,101/3,131/3,161/3,191/3,221/3;
47/3,27,115/3,149/3,61,217/3,251/3,95;
		

Crossrefs

Programs

  • Mathematica
    Select[Flatten[Table[(4*m*n+2*m+2*n-3)/3,{m,30},{n,m}]],IntegerQ] (* Harvey P. Dale, Jun 10 2015 *)

Extensions

Keyword:tabl removed, appearance of fractions clarified by R. J. Mathar, Oct 16 2009
Previous Showing 11-14 of 14 results.