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.

A286313 Union of A078561 and A078562.

Original entry on oeis.org

19, 31, 43, 61, 73, 79, 127, 157, 163, 229, 271, 349, 373, 379, 433, 439, 499, 607, 643, 673, 733, 751, 937, 967, 1009, 1093, 1213, 1279, 1291, 1429, 1489, 1543, 1549, 1597, 1609, 1657, 1777, 1861, 1987, 2131, 2203, 2287, 2341, 2347, 2371, 2383, 2389
Offset: 1

Views

Author

Zak Seidov, May 06 2017

Keywords

Comments

Number of terms among first 10^k primes, k=1..8:
0, 1, 17, 105, 646, 4385, 31721, 240346, 1884832.
E.g., k=1, first 10 primes are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, and only 19 is a term of the sequence. - Zak Seidov, May 08 2017
Primes p such that prime(p+2) = p + 10. - Harvey P. Dale, Jan 13 2022

Crossrefs

Cf. A078561 and A078562.

Programs

  • Maple
    select(p -> isprime(p) and isprime(p+10) and (isprime(p+4) xor isprime(p+6)), [seq(i,i=5..10000,2)]); # Robert Israel, May 08 2017
  • Mathematica
    Select[Prime[Range[1000]], NextPrime[#, 2] == # + 10 &]
    Select[Partition[Prime[Range[400]],3,1],#[[1]]+10==#[[3]]&][[All,1]] (* Harvey P. Dale, Jan 13 2022 *)

A078851 Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4, 6, 2]; short d-string notation of pattern = [462].

Original entry on oeis.org

19, 127, 229, 1009, 1279, 1597, 1609, 2539, 3319, 3529, 3907, 3919, 4639, 4789, 4999, 5839, 5857, 7477, 7537, 8419, 9619, 12097, 12907, 13327, 15259, 15877, 17569, 17977, 19069, 22027, 23017, 24967, 27739, 28537, 32359, 33577, 36919, 38317
Offset: 1

Views

Author

Labos Elemer, Dec 11 2002

Keywords

Comments

Subsequence of A078561. - R. J. Mathar, May 06 2017

Examples

			p=19,19+4=23,19+4+6=29,19+4+6+2=31 are consecutive primes.
		

Crossrefs

Cf. analogous prime quadruple sequences with various possible {2, 4, 6}-difference-patterns in brackets: A007530[242], A078847[246], A078848[264], A078849[266], A052378[424], A078850[426], A078851[462], A078852[466], A078853[624], A078854[626], A078855[642], A078856[646], A078857[662], A078858[664], A033451[666].

Programs

  • Mathematica
    Select[Prime@ Range[10^4], Differences@ Prime@ Range[#, # + 3] &@ PrimePi@ # == {4, 6, 2} &] (* Michael De Vlieger, Jul 02 2016 *)

Formula

Primes p = p(i) such that p(i+1)=p+4, p(i+2)=p+4+6, p(i+3)=p+4+6+2.

Extensions

Listed terms verified by Ray Chandler, Apr 20 2009

A078852 Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4, 6,6]; short d-string notation of pattern = [466].

Original entry on oeis.org

43, 163, 643, 937, 967, 1093, 1213, 2953, 4003, 4447, 6967, 7573, 8737, 9463, 10243, 10597, 11923, 12487, 12637, 13033, 14533, 14737, 15787, 16087, 16417, 16477, 16927, 17317, 17467, 20113, 22063, 25453, 26683, 26713, 27763, 29863, 32983
Offset: 1

Views

Author

Labos Elemer, Dec 11 2002

Keywords

Comments

Subsequence of A078561. - R. J. Mathar, Feb 11 2013

Examples

			p=43,43+4=47,43+4+6=53,43+4+6+6=59 are consecutive primes.
		

Crossrefs

Cf. analogous prime quadruple sequences with various possible {2, 4, 6}-difference-patterns in brackets: A007530[242], A078847[246], A078848[264], A078849[266], A052378[424], A078850[426], A078851[462], A078852[466], A078853[624], A078854[626], A078855[642], A078856[646], A078857[662], A078858[664], A033451[666].

Programs

  • Mathematica
    Transpose[Select[Partition[Prime[Range[4000]],4,1],Differences[#]=={4,6,6}&]][[1]] (* Harvey P. Dale, Dec 15 2015 *)
  • PARI
    isok(n) = isprime(n) && (nextprime(n+1) == (n+4)) && (nextprime(n+5) == (n+10)) && (nextprime(n+11) == (n+16)) \\ Michel Marcus, Jul 23 2013

Formula

Primes p = p(i) such that p(i+1)=p+4, p(i+2)=p+4+6, p(i+3)=p+4+6+6.

Extensions

Listed terms verified by Ray Chandler, Apr 20 2009

A078562 p, p+6 and p+10 are consecutive primes.

Original entry on oeis.org

31, 61, 73, 157, 271, 373, 433, 607, 733, 751, 1291, 1543, 1657, 1777, 1861, 1987, 2131, 2287, 2341, 2371, 2383, 2467, 2677, 2791, 2851, 3181, 3313, 3607, 3691, 4441, 4507, 4723, 4993, 5407, 5431, 5521, 5563, 5641, 5683, 5851, 6037, 6211, 6571, 6961
Offset: 1

Views

Author

Labos Elemer, Dec 10 2002

Keywords

Comments

Subsequence of A031924. - R. J. Mathar, Jun 15 2013

Examples

			Between p and p+10 the difference-pattern is [64] like e.g. for p=31: 31(6)37(4)41.
		

Crossrefs

Cf. analogous inter-prime d-patterns with d<=6: A022004[24], A022005[42], A049437[26], A049438[62], A078561[46], A078562[64], A047948[66].

Programs

  • Mathematica
    Transpose[Select[Partition[Prime[Range[1000]],3,1],#[[3]]-#[[1]]==10&&#[[2]]-#[[1]]==6&]][[1]] (* Harvey P. Dale, Dec 09 2010 *)
Showing 1-4 of 4 results.