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.

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A227286 First primes of arithmetic progressions of 13 primes each with the common difference 30030.

Original entry on oeis.org

14933623, 2085471361, 132420258931, 185041386139, 682539280751, 834172298383, 834172328413, 856378247603, 856378277633, 888867525577, 931115864233, 1059709587163, 1345030977911, 1360910561113, 1578280523803, 1973348047529, 1988253536611, 2083502941613
Offset: 1

Views

Author

Sameen Ahmed Khan, Jul 05 2013

Keywords

Comments

The minimal possible difference in an arithmetic progression of k primes is conjectured to be k# = A034386(k) for all k > 7. 13# = 30030.

Examples

			p = 2085471361 then the AP-13 is {2085471361, 2085501391, 2085531421, 2085561451, 2085591481, 2085621511, 2085651541, 2085681571, 2085711601, 2085741631, 2085771661, 2085801691, 2085831721} with the difference 13# = 2*3*5*7*11*13 = 30030.
		

Crossrefs

Programs

  • Mathematica
    Clear[p]; d = 30030; ap13p = {}; Do[If[PrimeQ[{p, p + d, p + 2*d, p + 3*d, p + 4*d, p + 5*d, p + 6*d, p + 7*d, p + 8*d, p + 9*d, p + 10*d, p + 11*d, p + 12*d}] == {True, True, True, True, True, True, True, True, True, True, True, True, True}, AppendTo[ap13p, p]], {p, 3, 41*10^9, 2}]; ap13p

Extensions

More terms from Jens Kruse Andersen, Jun 27 2014

A275682 Table read by rows: list of sexy prime quadruples (p, p+6, p+12, p+18) such that p+24 is composite.

Original entry on oeis.org

11, 17, 23, 29, 41, 47, 53, 59, 61, 67, 73, 79, 251, 257, 263, 269, 601, 607, 613, 619, 641, 647, 653, 659, 1091, 1097, 1103, 1109, 1481, 1487, 1493, 1499, 1601, 1607, 1613, 1619, 1741, 1747, 1753, 1759, 1861, 1867, 1873, 1879, 2371, 2377, 2383, 2389
Offset: 1

Views

Author

Arkadiusz Wesolowski, Aug 05 2016

Keywords

Comments

(5, 11, 17, 23, 29) is a sexy prime 5-tuple and this is the only sexy prime 5-tuple.
Essentially same as A123083.

Examples

			The table starts:
11, 17, 23, 29;
41, 47, 53, 59;
61, 67, 73, 79;
...
		

Crossrefs

Programs

  • Magma
    lst:=[]; for p in PrimesInInterval(7, 2371) do b:=p+6; if IsPrime(b) then c:=b+6; if IsPrime(c) then d:=c+6; if IsPrime(d) then lst:=lst cat [p, b, c, d]; end if; end if; end if; end for; lst;
  • Mathematica
    Most[#]&/@Select[Table[n + {0, 6, 12, 18, 24}, {n, Prime[Range[200]]}], PrimeQ[#]=={True, True, True, True, False}&]//Flatten (* Vincenzo Librandi, Jun 09 2017 *)
    #+{0,6,12,18}&/@Select[Prime[Range[400]],AllTrue[#+{6,12,18},PrimeQ] && CompositeQ[#+24]&]//Flatten (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 29 2019 *)

Formula

a(n) = A123083(n+4).

A377318 Numbers k such that prime(k), prime(k)+6, prime(k)+12, and prime(k)+18 are primes.

Original entry on oeis.org

3, 5, 13, 18, 54, 110, 116, 182, 234, 252, 271, 284, 351, 387, 464, 541, 551, 682, 709, 717, 741, 821, 829, 1171, 1417, 1448, 1510, 1594, 1711, 1726, 1842, 1853, 2009, 2086, 2209, 2297, 2408, 2600, 2680, 2876, 2924, 2930, 3253, 3303, 3437, 3977, 4384, 4431
Offset: 1

Views

Author

Kritsada Moomuang, Oct 24 2024

Keywords

Examples

			5 is in this sequence because: prime(5) = 11 and 11+6=17, 11+12=23, and 11+18=29 are all primes.
		

Crossrefs

Subsequence of A377317.

Programs

  • Mathematica
    Select[Range[1, PrimePi[50000]], PrimeQ[Prime[#] + 6] && PrimeQ[Prime[#] + 12] && PrimeQ[Prime[#] + 18] &]
    Select[Range[4500],AllTrue[Prime[#]+{0,6,12,18},PrimeQ]&] (* Harvey P. Dale, Jun 17 2025 *)
  • PARI
    for(k=1, primepi(50000), p = prime(k); if(isprime(p+6) && isprime(p+12) && isprime(p+18), print(k)))

Formula

a(n) = pi(A023271(n)).

A092519 Smallest prime a(n) such that a(n)+6n, a(n)+12n and a(n)+18n are also primes.

Original entry on oeis.org

5, 5, 5, 59, 7, 31, 5, 5, 5, 11, 31, 7, 23, 5, 11, 5, 7, 23, 79, 29, 5, 5, 73, 29, 7, 41, 107, 43, 19, 59, 11, 37, 13, 79, 13, 11, 17, 43, 359, 23, 31, 5, 53, 19, 47, 181, 137, 23, 59, 7, 491, 127, 283, 179, 23, 11, 7, 5, 89, 7, 461, 7, 53, 139, 31, 5, 7, 13
Offset: 1

Views

Author

Ray G. Opao, Apr 06 2004

Keywords

Examples

			a(5) = 7: 7+6*5 = 7+30 = 37, 7+12*5 = 7+60 = 67, and 7+18*5 = 7+90 = 97 are all prime.
		

Crossrefs

a(1) starts sequence A023271.

Programs

  • Magma
    prs := [NthPrime(i) : i in [1..200]]; result := []; for n in [1..100] do  for p in prs do if forall{k : k in [1..3] | IsPrime(p + 6*n*k)} then  Append(~result, p); break; end if; end for; end for; result; // Vincenzo Librandi, Jul 26 2025
  • Mathematica
    Module[{nn=100,prs},prs=Prime[Range[nn]];Table[SelectFirst[prs, AllTrue[ #+6*Range[3]*n,PrimeQ]&],{n,nn/2}]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 22 2018 *)

A160264 Least prime of a 6-tuplet that contains both a prime quadruple and a sexy prime quadruple.

Original entry on oeis.org

11, 1481, 1861, 5641, 88801, 165701, 266671, 284731, 326141, 402751, 626611, 661091, 855721, 959461, 1022501, 1068241, 1068701, 1118851, 1146781, 1155601, 1246361, 1461401, 1573921, 1830331, 1917731, 2674531, 2683771, 3058871
Offset: 1

Views

Author

Ki Punches, May 05 2009

Keywords

Comments

Sequence is probably infinite.

Examples

			6-tuplet 5641 5647 5651 5653 5657 5659, contains sexy prime quadruple 5641 5647 5653 5659, and prime quadruple 5651 5653 5657 5659.
		

Crossrefs

Programs

  • Mathematica
    stQ[n_]:=Module[{ss4=Subsets[n,{4}]},AnyTrue[ss4,Differences[#]=={6,6,6}&] && AnyTrue[ss4,Differences[#]=={2,4,2}&]]; Select[Partition[Prime[ Range[ 221000]],6,1],stQ][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 24 2020 *)

Extensions

Extended by Ray Chandler, May 23 2009

A163857 Number of sexy prime quadruples (p, p+6, p+12, p+18), with p <= n.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
Offset: 1

Views

Author

Daniel Forgues, Aug 05 2009

Keywords

Comments

There are 2 sexy prime quadruples classes, (-1, -1, -1, -1) (mod 6) and (+1, +1, +1, +1) (mod 6). They should asymptotically have the same number of quadruples, if there is an infinity of such quadruples, although with a Chebyshev bias expected against the quadratic residue class quadruples (+1, +1, +1, +1) (mod 6), which doesn't affect the asymptotic result. This sequence counts both classes.
Also the sexy prime quadruples of class (-1, -1, -1, -1) (mod 6) are (11, 17, 23, 29) (mod 30) while the sexy prime quadruples of class (+1, +1, +1, +1) (mod 6) are (1, 7, 13, 19) (mod 30).
Except for (5, 11, 17, 23, 29), there is no sexy prime quintuples (p, p+6, p+12, p+18, p+24) since one of the members is then divisible by 5.

Crossrefs

A023271 First member of a sexy prime quadruple: value of p where (p, p+6, p+12, p+18) are all prime.
A046122 Second member of a sexy prime quadruple: value of p+6 where (p, p+6, p+12, p+18) are all prime.
A046123 Third member of a sexy prime quadruple: value of p+12 where (p, p+6, p+12, p+18) are all prime.
A046124 Last member of a sexy prime quadruple: value of p+18 where (p, p+6, p+12, p+18) are all prime.

A357909 Primes p such that p+6, p+12, p+18, 4*p+37, 4*p+43, 4*p+49 and 4*p+55 are also all primes.

Original entry on oeis.org

408211, 6375751, 6433741, 6718471, 19134931, 25280791, 63908851, 67078801, 152418151, 159268561, 217697911, 236220991, 237943591, 334030981, 363246211, 392644921, 406249171, 410652031, 428032441, 476660281, 478441291, 502777111, 552727711, 552855001, 554201731, 693654721, 816050071, 877207141
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Nov 09 2022

Keywords

Comments

Start of a "sexy" prime quadruple (in the sense of A023271) such that 1 + the sum of the quadruple is the start of another "sexy" prime quadruple.
All terms == 1 (mod 30).

Examples

			a(1) = 408211 is a term because 408211, 408211+6 = 408217, 408211+12 = 408223, 408211+18 = 408229 are primes (a "sexy" prime quadruple), the sum of this quadruple is 4*408211+36 = 1632880, and 1632880+1 = 1632881, 1632880+7 = 1632887, 1632880+13 = 1632893, 1632880+19 = 1632899 is another "sexy" prime quadruple.
		

Crossrefs

Cf. A023271.

Programs

  • Maple
    Res:= NULL: count:= 0:
    for p from 1 by 30 while count < 40 do
      if isprime(p) and isprime(p+6) and isprime(p+12) and isprime(p+18)
      and isprime(4*p+37) and isprime(4*p+43) and isprime(4*p+49) and isprime(4*p+55)
    then Res:= Res, p; count:= count+1
    fi
    od:
    Res;

A358322 Interlopers in sexy prime quadruples.

Original entry on oeis.org

7, 13, 19, 43, 71, 617, 643, 1093, 1483, 1489, 1609, 1871, 1877, 2381, 2687, 3919, 4003, 5441, 5651, 5657, 9463, 11831, 12109, 14629, 20357, 21491, 24107, 26683, 26713, 32059, 37571, 41957, 42407, 44533, 50591, 55217, 65717, 68899, 70001, 79813, 87557, 88811, 88817, 103993, 110923, 112573, 122029
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Nov 09 2022

Keywords

Comments

Primes q !== p (mod 6) such that p < q < p+18, where (p, p+6, p+12, p+18) is a "sexy" prime quadruple, i.e., p is in A023271.

Examples

			a(5) = 71 is a term because it is a prime !== 61 (mod 6) with 61 < 71 < 79, where (61, 67, 73, 79) is a sexy prime quadruple.
		

Crossrefs

Cf. A023271.

Programs

  • Maple
    Res:= 7: count:= 1:
    for p from 11 by 10 while count < 100 do
      if andmap(isprime, [p, p+6, p+12, p+18]) then
        R:= select(isprime, [p+2, p+8, p+10, p+16]);
        count:= count + nops(R);
        Res:= Res, op(R);
      fi
    od:
    Res;

A358343 Primes p such that p + 6, p + 12, p + 18, (p+4)/5, (p+4)/5 + 6, (p+4)/5 + 12 and (p+4)/5 + 18 are also prime.

Original entry on oeis.org

213724201, 336987901, 791091901, 1940820901, 2454494551, 2525191051, 2675901751, 3490984201, 3571597951, 3702692551, 4045565851, 4531570951, 5698472701, 5928161251, 5953041001, 6589503751, 7073836201, 7360771801, 7811308951, 8282895451, 10242069451, 11049315751, 12392801251, 13062696001
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Nov 10 2022

Keywords

Comments

Terms p of A023271 such that (p+4)/5 is also in A023271.
All terms == 901 (mod 1050).

Examples

			a(3) = 791091901 is a term because p = 791091901, p + 6 = 791091907, p + 12 = 791091913, p + 18 = 791091919, (p+4)/5 = 158218381, (p+4)/5 + 6 = 158218387, (p+4)/5 + 12 = 158218393, and (p+4)/5 + 18 = 158218399 are all prime.
		

Crossrefs

Cf. A023271.

Programs

  • Maple
    filter:= p -> andmap(isprime, [p, p+6, p+12, p+18, (p+4)/5, (p+4)/5 + 6,
    (p+4)/5 + 12, (p+4)/5 + 18]):
    select(filter, [seq(p, p = 901 .. 2*10^10, 1050)]);

A372042 Monogamously Faithful Primes (primes that are sexy primes with only one other prime in their pair).

Original entry on oeis.org

83, 89, 131, 137, 191, 193, 197, 199, 223, 229, 307, 311, 313, 317, 331, 337, 383, 389, 433, 439, 443, 449, 457, 461, 463, 467, 503, 509, 541, 547, 571, 577, 677, 683, 751, 757, 821, 823, 827, 829, 853, 857, 859, 863, 877, 881, 883, 887, 991, 997, 1013, 1019, 1033, 1039, 1063, 1069, 1087
Offset: 0

Views

Author

Ryan Stoler, Apr 17 2024

Keywords

Comments

These are all the numbers found in A136207 but not found in A046118, A046119, A046120, A023271, A046122, A046123, or A046124, i.e., members of a sexy prime pair but not members of sexy prime triplets, quadruplets, ...

Examples

			83 and 89 are "sexy" with each other, because they differ by 6. They are monogamously faithful, because neither is sexy with any other number.
71 is not "sexy" because it is not in A136207.
67 is "sexy" with both 61 and 73. Therefore, it is not monogamously faithful, since it has multiple numbers that it is sexy with.
43 is "sexy" only with 37. But it is not monogamously faithful, even though it isn't sexy with another number, because 37 is also "sexy" with 31, therefore "cheating" on 43 with 31.
		

Crossrefs

Programs

  • Maple
    isA372042 := proc(n)
        if isprime(n) then
            if isprime(n+6) then
                if not isprime(n-6) and not isprime(n+12) then
                    true;
                else
                    false;
                end if;
            elif isprime(n-6) then
                if not isprime(n+6) and not isprime(n-12) then
                    true;
                else
                    false;
                end if;
            else
                false ;
            end if;
        else
            false ;
        end if;
    end proc:
    A372042 := proc(n)
        option remember;
        local a;
        if n = 1 then
            83 ;
        else
            a := nextprime(procname(n-1)) ;
            while true do
                if isA372042(a) then
                    return a;
                else
                    a := nextprime(a) ;
                end if;
            end do:
        end if;
    end proc:
    seq(A372042(n),n=1..80) ; # R. J. Mathar, Jun 10 2024
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