A098416 (A007529(n) + A098415(n)) / 4.
4, 5, 7, 8, 10, 20, 22, 35, 50, 52, 53, 55, 97, 98, 113, 115, 140, 155, 157, 175, 230, 232, 308, 322, 412, 413, 428, 430, 440, 442, 545, 547, 640, 650, 652, 713, 715, 725, 742, 743, 745, 805, 833, 848, 893, 935, 937, 938, 998, 1000, 1042, 1043, 1070, 1120, 1135
Offset: 1
Keywords
A098417 A098414(n) - (A007529(n) + A098415(n))/2.
-1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, 1, -1, 1, 1, -1, -1, 1, -1, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, -1, 1, 1, 1, 1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, -1, -1, 1, 1, -1, -1, 1, -1, -1, -1, 1, -1, 1, 1, -1
Offset: 1
Keywords
Comments
Links
- Eric Weisstein's World of Mathematics, Prime Triplet
A023201 Primes p such that p + 6 is also prime. (Lesser of a pair of sexy primes.)
5, 7, 11, 13, 17, 23, 31, 37, 41, 47, 53, 61, 67, 73, 83, 97, 101, 103, 107, 131, 151, 157, 167, 173, 191, 193, 223, 227, 233, 251, 257, 263, 271, 277, 307, 311, 331, 347, 353, 367, 373, 383, 433, 443, 457, 461, 503, 541, 557, 563, 571, 587, 593, 601, 607, 613, 641, 647
Offset: 1
Links
- T. D. Noe, Table of n, a(n) for n = 1..10000
- Maxie D. Schmidt, New Congruences and Finite Difference Equations for Generalized Factorial Functions, arXiv:1701.04741 [math.CO], 2017.
- Eric Weisstein's World of Mathematics, Sexy Primes. [The definition in this webpage is unsatisfactory, because it defines a "sexy prime" as a pair of primes.- _N. J. A. Sloane_, Mar 07 2021].
- Wikipedia, Sexy prime.
Crossrefs
Programs
-
Haskell
a023201 n = a023201_list !! (n-1) a023201_list = filter ((== 1) . a010051 . (+ 6)) a000040_list -- Reinhard Zumkeller, Feb 25 2013
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Magma
[n: n in [0..40000] | IsPrime(n) and IsPrime(n+6)]; // Vincenzo Librandi, Aug 04 2010
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Maple
A023201 := proc(n) option remember; if n = 1 then 5; else for a from procname(n-1)+2 by 2 do if isprime(a) and isprime(a+6) then return a; end if; end do: end if; end proc: # R. J. Mathar, May 28 2013
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Mathematica
Select[Range[10^2], PrimeQ[ # ]&&PrimeQ[ #+6] &] (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *) Select[Prime[Range[120]],PrimeQ[#+6]&] (* Harvey P. Dale, Mar 20 2018 *)
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PARI
is(n)=isprime(n+6)&&isprime(n) \\ Charles R Greathouse IV, Mar 20 2013
A022004 Initial members of prime triples (p, p+2, p+6).
5, 11, 17, 41, 101, 107, 191, 227, 311, 347, 461, 641, 821, 857, 881, 1091, 1277, 1301, 1427, 1481, 1487, 1607, 1871, 1997, 2081, 2237, 2267, 2657, 2687, 3251, 3461, 3527, 3671, 3917, 4001, 4127, 4517, 4637, 4787, 4931, 4967, 5231, 5477
Offset: 1
Comments
Subsequence of A001359. - R. J. Mathar, Feb 10 2013
All terms are congruent to 5 (mod 6). - Matt C. Anderson, May 22 2015
Links
- Matt C. Anderson Table of n, a(n) for n = 1..10000 (terms 1..1000 from T. D. Noe)
- T. Forbes and Norman Luhn, Prime k-tuplets
- R. J. Mathar, Table of Prime Gap Constellations (2013,2024), 275 pages (no not print...)
- Thomas R. Nicely, Enumeration of the prime triples (q,q+2,q+6) to 1e16.
- P. Pollack, Analytic and Combinatorial Number Theory, Course Notes, p. 132, ex. 3.4.3. [Broken link?]
- P. Pollack, Analytic and Combinatorial Number Theory, Course Notes, p. 132, ex. 3.4.3.
- Maxie D. Schmidt, New Congruences and Finite Difference Equations for Generalized Factorial Functions, arXiv:1701.04741 [math.CO], 2017.
- Eric Weisstein's World of Mathematics, Prime Triplet
- Index entries for primes, gaps between
Crossrefs
Programs
-
Magma
[ p: p in PrimesUpTo(10000) | IsPrime(p+2) and IsPrime(p+6) ] // Vincenzo Librandi, Nov 19 2010
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Maple
A022004 := proc(n) if n= 1 then 5; else for a from procname(n-1)+2 by 2 do if isprime(a) and isprime(a+2) and isprime(a+6) then return a; end if; end do: end if; end proc: # R. J. Mathar, Jul 11 2012
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Mathematica
Select[Prime[Range[1000]], PrimeQ[#+2] && PrimeQ[#+6]&] (* Vladimir Joseph Stephan Orlovsky, Mar 30 2011 *) Transpose[Select[Partition[Prime[Range[1000]],3,1],Differences[#]=={2,4}&]][[1]] (* Harvey P. Dale, Dec 24 2011 *)
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PARI
is(n)=isprime(n)&&isprime(n+2)&&isprime(n+6) \\ Charles R Greathouse IV, Jul 01 2013
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Python
from sympy import primerange def aupto(limit): p, q, alst = 2, 3, [] for r in primerange(5, limit+7): if p+2 == q and p+6 == r: alst.append(p) p, q = q, r return alst print(aupto(5477)) # Michael S. Branicky, May 11 2021
A022005 Initial members of prime triples (p, p+4, p+6).
7, 13, 37, 67, 97, 103, 193, 223, 277, 307, 457, 613, 823, 853, 877, 1087, 1297, 1423, 1447, 1483, 1663, 1693, 1783, 1867, 1873, 1993, 2083, 2137, 2377, 2683, 2707, 2797, 3163, 3253, 3457, 3463, 3847, 4153, 4513, 4783, 5227, 5413, 5437, 5647, 5653, 5737, 6547
Offset: 1
Comments
Subsequence of A029710. - R. J. Mathar, May 06 2017
All terms are congruent to 1 (modulo 6). - Matt C. Anderson, May 22 2015
Links
- Matt C. Anderson, Table of n, a(n) for n = 1..10000 (terms 1..1000 from T. D. Noe).
- Tony Forbes and Norman Luhn, Prime k-tuplets.
- Maxie D. Schmidt, New Congruences and Finite Difference Equations for Generalized Factorial Functions, arXiv:1701.04741 [math.CO], 2017.
- Eric Weisstein's World of Mathematics, Prime Triplet.
Crossrefs
Programs
-
Magma
[p: p in PrimesUpTo(10000) | IsPrime(p+4) and IsPrime(p+6)]; // Vincenzo Librandi, Aug 23 2015
-
Mathematica
Select[Table[Prime[n], {n, 2000}], PrimeQ[# + 4] && PrimeQ[# + 6] &] (* Vladimir Joseph Stephan Orlovsky, Jun 19 2011 *)
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PARI
select(p->isprime(p+4) && isprime(p+6), primes(1000)) \\ Charles R Greathouse IV, Mar 17 2023
A031924 Primes followed by a gap of 6, i.e., next prime is p + 6.
23, 31, 47, 53, 61, 73, 83, 131, 151, 157, 167, 173, 233, 251, 257, 263, 271, 331, 353, 367, 373, 383, 433, 443, 503, 541, 557, 563, 571, 587, 593, 601, 607, 647, 653, 677, 727, 733, 751, 941, 947, 971, 977, 991, 1013, 1033, 1063, 1097, 1103, 1117, 1123, 1181
Offset: 1
Keywords
Comments
Original name: Lower prime of a difference of 6 between consecutive primes.
Conjecture: The sequence is infinite and for every n >= 7746, a(n+1) < a(n)^(1+1/n). Namely for n >= 7746, a(n)^(1/n) is a strictly decreasing function of n (See comment lines of the sequence A248855). - Jahangeer Kholdi and Farideh Firoozbakht, Nov 29 2014
Examples
23 is a term as the next prime 29 = 23 + 6.
Links
- Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
- OEIS wiki, Consecutive primes in arithmetic progression: CPAP with given gap, updated Jan. 2020
- Index entries for primes, gaps between
Programs
-
GAP
P:=Filtered([1..1200],IsPrime);; List(Filtered([1..Length(P)-1],i->P[i+1]-P[i]=6),k->P[k]); # Muniru A Asiru, Jan 30 2019
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Magma
[p: p in PrimesUpTo(1200) | NextPrime(p)-p eq 6]; // Bruno Berselli, Apr 09 2013
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Maple
A031924 := proc(n) option remember; if n = 1 then return 23; else p := nextprime(procname(n-1)) ; q := nextprime(p) ; while q-p <> 6 do p := q ; q := nextprime(p) ; end do: return p; end if; end proc: # R. J. Mathar, Jan 23 2013
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Mathematica
Transpose[Select[Partition[Prime[Range[200]], 2, 1], Last[#] - First[#] == 6 &]][[1]] (* Bruno Berselli, Apr 09 2013 *)
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PARI
is(n)=isprime(n)&&nextprime(n+1)-n==6 \\ Charles R Greathouse IV, Mar 21 2013
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PARI
apply( A031924(n,p=2,show=0,g=6)={forprime(q=p+1,, p+g!=(p=q) || (show&&print1(p-g",")) || n-- || return(p-g))}, [1..99]) \\ Use nxt(p)=A031924(1,p) to get the term following p, use show=1 to print all a(1..n), g to select a different gap. - M. F. Hasler, Jan 02 2020
Extensions
New name from M. F. Hasler, Jan 02 2020
A086140 Primes p such that three (the maximum number) primes occur between p and p+12.
5, 7, 11, 97, 101, 1481, 1867, 3457, 5647, 15727, 16057, 16061, 19417, 19421, 21011, 22271, 43777, 43781, 55331, 79687, 88807, 101107, 144161, 165701, 166841, 195731, 201821, 225341, 247601, 257857, 266677, 268811, 276037, 284737, 326141, 340927
Offset: 1
Keywords
Comments
p+12 must be a prime. - Harvey P. Dale, Jun 11 2015
A086140 is the union of A022006 and A022007. By merging the two b-files I have extended the current b-file up to n=10000 (nearly n=20000 would have been possible). I add a comparison (see Links) between the frequency of prime 5-tuples and an asymptotic approximation, which is unproven but likely to be true, and based on a conjecture first published by Hardy and Littlewood in 1923. Twins, triples and quadruplets are treated as well. - Gerhard Kirchner, Dec 07 2016
Examples
There are two types of prime 5-tuples, and both are represented in this sequence. (11, 13, 17, 19, 23) is a prime 5-tuple of the form (p, p+2, p+6, p+8, p+12), so 11 is in the sequence, and (97, 101, 103, 107, 109) is a prime 5-tuple of the form (p, p+4, p+6, p+10, p+12), so 97 is in the sequence. - _Michael B. Porter_, Dec 19 2016
Links
- Harvey P. Dale and Gerhard Kirchner, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harvey P. Dale)
- Gerhard Kirchner, Comparison with an assumed asymptotic distribution
Crossrefs
Programs
-
Mathematica
cp[x_, y_] := Count[Table[PrimeQ[i], {i, x, y}], True] {d=12, k=0}; Do[s=Prime[n]; s1=Prime[n+1]; If[PrimeQ[s+d]&&Equal[cp[s+1, s+d-1], 3], k=k+1; Print[s]], {n, 1, 100000}] (* Second program: *) Transpose[Select[Partition[Prime[Range[30000]],5,1],#[[5]]-#[[1]] == 12&]][[1]] (* Harvey P. Dale, Jun 11 2015 *)
A257124 Initial members of prime septuplets.
11, 5639, 88799, 165701, 284729, 626609, 855719, 1068701, 1146779, 6560999, 7540439, 8573429, 11900501, 15760091, 17843459, 18504371, 19089599, 21036131, 24001709, 25658441, 39431921, 42981929, 43534019, 45002591, 67816361, 69156539, 74266259, 79208399, 80427029, 84104549, 86818211, 87988709, 93625991, 124066079
Offset: 1
Keywords
Links
- Tim Johannes Ohrtmann, Table of n, a(n) for n = 1..1990
- Tony Forbes, k-tuplets
Crossrefs
Formula
A257125 Initial members of prime 9-tuplets (or nonuplets).
7, 11, 13, 17, 1277, 88789, 113143, 113147, 855709, 74266249, 182403491, 226449521, 252277007, 408936947, 521481197, 626927443, 910935911, 964669609, 1042090781, 1116452627, 1209950867, 1422475909, 1459270271, 1645175087, 2117861719, 2335215973, 2558211559, 2843348351, 2873599429, 2966003057, 3447123283, 3947480417
Offset: 1
Keywords
Comments
Primes prime(m) such that prime(m+8) = prime(m) + 30. - Zak Seidov, Jul 06 2015
Links
- Zak Seidov, Table of n, a(n) for n = 1..651 (Essentially original b-file by Tim Johannes Ohrtmann, just added a(1)=7 and corrected EndOfFile)
- Tony Forbes and Norman Luhn, Smallest Prime k-tuplets
Crossrefs
Programs
-
Magma
[NthPrime(n): n in [0..2*10^4] | NthPrime(n+8) eq (NthPrime(n) + 30)]; // Vincenzo Librandi, Jul 08 2015
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Mathematica
{p, q, r, s, t, u, v, w, x} = Prime@ Range@ 9; lst = {}; While[p < 1000000001, If[p + 30 == x, AppendTo[lst, p]; Print@ p]; {p, q, r, s, t, u, v, w, x} = {q, r, s, t, u, v, w, x, NextPrime@ x}]; lst (* Robert G. Wilson v, Jul 06 2015 *) Select[Partition[Prime[Range[5 10^6]],9,1],#[[1]]+30==#[[9]]&][[;;,1]] (* The program generates the first 10 terms of the sequence. To generate more, increase the Range constant. *) (* Harvey P. Dale, Jul 01 2024 *)
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PARI
main(size)=v=vector(size); i=0; m=1; while(i
Anders Hellström, Jul 08 2015
A257127 Initial members of prime 10-tuplets (or decaplets).
11, 9853497737, 21956291867, 22741837817, 33081664151, 83122625471, 164444511587, 179590045487, 217999764107, 231255798857, 242360943257, 294920291201, 573459229151, 663903555851, 666413245007, 688697679401, 696391309697, 730121110331, 867132039857, 974275568237, 976136848847, 1002263588297
Offset: 1
Keywords
Links
- M. F. Hasler, Table of n, a(n) for n = 1..10000 (first 101 terms from Tim Johannes Ohrtmann), Mar 01 2022
- Tony Forbes and Norman Luhn Prime k-tuplets
- Norman Luhn, The big database of "The smallest prime k-tuplets", section "10-tuplets": up to 10^20 as of March 2022.
Comments
Links