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.

A101448 Nonnegative numbers k such that 2k + 11 is prime.

Original entry on oeis.org

0, 1, 3, 4, 6, 9, 10, 13, 15, 16, 18, 21, 24, 25, 28, 30, 31, 34, 36, 39, 43, 45, 46, 48, 49, 51, 58, 60, 63, 64, 69, 70, 73, 76, 78, 81, 84, 85, 90, 91, 93, 94, 100, 106, 108, 109, 111, 114, 115, 120, 123, 126, 129, 130, 133, 135, 136, 141, 148, 150, 151, 153, 160, 163
Offset: 1

Views

Author

Parthasarathy Nambi, Jan 24 2005

Keywords

Comments

2 is the smallest single-digit prime and 11 is the smallest two-digit prime.

Examples

			If n=1, then 2*1 + 11 = 13 (prime).
If n=49, then 2*49 + 11 = 109 (prime).
If n=69, then 2*69 + 11 = 149 (prime).
		

Crossrefs

Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), this seq (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).
Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), A089253 (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Programs

Extensions

More terms from Stefan Steinerberger, Feb 28 2006
Definition clarified by Zak Seidov, Jul 11 2014

A101086 Numbers k for which 997*k + 1009 is prime.

Original entry on oeis.org

0, 6, 10, 12, 22, 36, 64, 76, 82, 94, 126, 130, 136, 144, 150, 162, 174, 186, 202, 204, 246, 250, 252, 274, 276, 292, 294, 300, 306, 312, 330, 342, 360, 364, 390, 430, 466, 472, 480, 484, 490, 502, 526, 540, 546, 582, 586, 592, 594, 606, 610, 616, 622, 642
Offset: 1

Views

Author

Parthasarathy Nambi, Jan 21 2005

Keywords

Comments

997 is the largest three-digit prime and 1009 is the smallest four-digit prime.

Examples

			If k=6, then 997*6 + 1009 = 6991 (prime).
If k=10, then 997*10 + 1009 = 10979 (prime).
If k=12, then 997*12 + 1009 = 12973 (prime).
		

Crossrefs

Programs

  • Magma
    [ n: n in [0..700] | IsPrime(997*n + 1009) ]; // Vincenzo Librandi, Feb 04 2011
  • Mathematica
    Select[Range[0,700],PrimeQ[997#+1009]&] (* Harvey P. Dale, Jun 29 2011 *)

Extensions

Extended by Ray Chandler, Jan 25 2005

A101084 Numbers k such that 97*k + 101 is a prime.

Original entry on oeis.org

0, 6, 8, 14, 18, 30, 36, 50, 86, 90, 96, 110, 114, 116, 126, 128, 134, 138, 140, 156, 158, 174, 186, 194, 200, 204, 218, 236, 258, 260, 266, 278, 294, 296, 300, 314, 326, 336, 338, 344, 348, 354, 366, 368, 378, 398, 420, 428, 468, 470, 476, 498, 504, 516, 524
Offset: 1

Views

Author

Parthasarathy Nambi, Jan 21 2005

Keywords

Comments

97 is the largest two-digit prime and 101 is the smallest three-digit prime.

Examples

			If k=6, then 97*6 + 101 = 683 (prime).
If k=8, then 97*8 + 101 = 877 (prime).
If k=14, then 97*14 + 101 = 1459 (prime).
		

Crossrefs

Programs

Extensions

Extended by Ray Chandler, Jan 25 2005

A101444 Numbers k such that (9973*k + 10007) is a prime.

Original entry on oeis.org

0, 14, 32, 42, 48, 98, 104, 108, 120, 122, 132, 180, 204, 210, 224, 228, 230, 264, 278, 300, 302, 308, 318, 342, 344, 348, 350, 374, 384, 402, 410, 414, 428, 438, 444, 462, 470, 500, 522, 540, 564, 602, 614, 638, 644, 672, 678, 692, 698, 714, 720, 740, 782
Offset: 1

Views

Author

Parthasarathy Nambi, Jan 18 2005

Keywords

Comments

Note that 9973 is the largest four-digit prime and 10007 is the smallest five-digit prime.

Examples

			If k=14 then 9973*14 + 10007 = 149629 (prime).
If k=32 then 9973*32 + 10007 = 329143 (prime).
If k=42 then 9973*42 + 10007 = 428873 (prime).
		

Crossrefs

Programs

  • Mathematica
    Select[ Range[ 0, 791], PrimeQ[9973# + 10007]&] (* Robert G. Wilson v, Jan 20 2005 *)

Extensions

Extended by Lior Manor, Ray Chandler and Robert G. Wilson v, Jan 20 2005

A108110 Numbers n such that prime(k)*n+prime(k+1), for k=1,...,6 all are primes.

Original entry on oeis.org

284, 3074, 3494, 21698, 32138, 43874, 51794, 60674, 75494, 407348, 437438, 459794, 571478, 660878, 667358, 705464, 716624, 740774, 811028, 820154, 910664, 1059398, 1077998, 1122584, 1150748, 1210754, 1222898, 1265018, 1412174, 1461164, 1486574, 1585868, 1631438
Offset: 1

Views

Author

Zak Seidov, Jun 03 2005

Keywords

Comments

n == 0 (mod 2). n == 2 (mod 3). n == 3 or 4 (mod 5). - Jason Yuen, Sep 02 2024

Examples

			284 is OK because 2*284+3, 3*284+5, 5*284+7, 7*284+11, 11*284+13 and 13*284+17 all are primes.
		

Crossrefs

Cf. A067076 (k=1), A088879 (k=2), A111224 (k=3), A101123 (k=4), A102721 (k=5).
Cf. A108117 (k=1..7), A379427 (k=1..8).

Programs

  • Mathematica
    s={};Do[If[Union[PrimeQ/@Table[Prime[k]*n+Prime[k+1], {k, 6}]]=={True}, s=Append[s, n]], {n, 2, 1000000, 2}];s
  • PARI
    \\ See isok from A108117
    for(n=1,2*10^6,if(isok(n,6),print1(n", "))) \\ Jason Yuen, Sep 02 2024

Extensions

a(22)-a(33) from Jason Yuen, Sep 02 2024

A108117 Numbers n such that prime(k)*n+prime(k+1), for k=1,...,7 all are primes.

Original entry on oeis.org

3494, 60674, 75494, 1122584, 2136044, 2473934, 3367244, 5600384, 6629804, 6910784, 7554644, 8572904, 10079144, 11848094, 11892164, 12043214, 12167594, 12269234, 12507284, 12700154, 13459664, 13924544, 14495354, 15005954, 16890914, 17827094, 20642984, 25796054
Offset: 1

Views

Author

Zak Seidov, Jun 03 2005

Keywords

Comments

The only n, for which also 19*3494+23 is prime, is n=5600384. In principle, n == 4 (mod 10) can give primes of the form prime(k)*n+prime(k+1), for all k from 1 up to 41, while prime(42)*4+prime(43)=181*4+191 == 5 (mod 10) that is nonprime. It'd be very interesting to find at least one n such that prime(k)*n+prime(k+1), k=1,...,41 are all prime.
There are no values of n such that prime(k)*n+prime(k+1), k=1,...,9 are all prime. Proof: If n = 3*i then 2*(3*i)+3 = 3*(2*i+1) is not prime. If n = 3*i+1 then 5*(3*i+1)+7 = 3*(5*i+4) is not prime. If n = 3*i+2 then 23*(3*i+2)+29 = 3*(23*i+25) is not prime. - Jason Yuen, Sep 02 2024

Examples

			3494 is OK because 2*3494+3, 3*3494+5, 5*3494+7, 7*3494+11, 11*3494+13, 13*3494+17 and 17*3494+19 all are primes.
		

Crossrefs

Cf. A067076 (k=1), A088879 (k=2), A111224 (k=3), A101123 (k=4), A102721 (k=5), A108976 (k=7).
Cf. A108110 (k=1..6), A379427 (k=1..8).

Programs

  • Mathematica
    s={};Do[If[Union[PrimeQ/@Table[Prime[k]*n+Prime[k+1], {k, 7}]]=={True}, s=Append[s, n]], {n, 4, 10000000, 10}];s
    Select[Range[9*10^6],AllTrue[Prime[Range[7]]#+Prime[Range[2,8]],PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 24 2018 *)
  • PARI
    isok(n,upto=7)=for(k=1,upto,if(!isprime(prime(k)*n+prime(k+1)),return(0)));1
    for(n=1,3*10^7,if(isok(n),print1(n", "))) \\ Jason Yuen, Sep 02 2024

Extensions

a(13)-a(28) from Jason Yuen, Sep 02 2024

A153350 Numbers n such that 7n+11 is not prime.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 15, 16, 17, 19, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 69, 70, 71, 72, 73, 74, 75, 76, 77, 79, 81, 82, 83, 85, 87, 88, 89
Offset: 1

Views

Author

Vincenzo Librandi, Dec 24 2008

Keywords

Examples

			Distribution of the even terms in the following triangular array:
*;
*,2;
*,*,*;
*,*,*,10;
*,*,*,*,*;
4,*,*,*,*,*;
*,*,*,*,22,*,*;
*,*,*,*,*,30,*,*;
*,12,*,*,*,*,*,*,50;
*,*,*,*,*,*,*,*,*,*;
*,*,*,28,*,*,*,*,*,*,74;
*,*,*,*,*,*,52,*,*,*,*,*;
10,*,*,*,*,*,*,64,*,*,*,*,*; etc.
where * marks the non-integer values of (4*h*k + 2*k + 2*h - 10)/7 with h >= k >= 1. - _Vincenzo Librandi_, Jan 17 2013
		

Crossrefs

Cf. A101123.

Programs

  • Magma
    [n: n in [0..150] | not IsPrime(7*n+11)]; // VIncenzo Librandi, Jan 13 2013
  • Mathematica
    Select[Range[200], !PrimeQ[7 # + 11] &] (* Vincenzo Librandi, Jan 13 2013 *)
  • PARI
    isA153350(n)=!isprime(7*n+11)
    

Extensions

Corrected and edited by Michael B. Porter, Apr 20 2010

A101503 Numbers k such that 11*k + 101 is prime.

Original entry on oeis.org

0, 6, 10, 12, 16, 28, 30, 40, 42, 46, 52, 58, 60, 66, 76, 88, 90, 100, 102, 108, 118, 126, 130, 132, 136, 138, 142, 160, 168, 172, 180, 192, 208, 210, 216, 220, 222, 228, 238, 240, 250, 256, 258, 268, 276, 280, 282, 292, 306, 310, 312, 322, 328, 336, 342, 346
Offset: 1

Views

Author

Parthasarathy Nambi, Jan 24 2005

Keywords

Comments

11 is the smallest two-digit prime and 101 is the smallest three-digit prime.

Examples

			If k=0, then 11*0 + 101 = 101 (prime).
If k=6, then 11*6 + 101 = 167 (prime).
If k=60, then 11*60 + 101 = 761 (prime).
		

Crossrefs

Programs

Extensions

More terms from Stefan Steinerberger, Feb 28 2006
Showing 1-8 of 8 results.