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.

A104229 Primes equal to the product of two successive sexy primes plus 6.

Original entry on oeis.org

61, 97, 193, 397, 673, 1153, 1597, 1933, 4093, 7393, 12097, 37633, 64513, 70753, 96097, 122497, 126733, 136897, 190093, 211597, 256033, 313597, 329473, 348097, 430333, 541693, 781453, 891133, 988033, 1267873, 1416097, 1674433, 2102497
Offset: 1

Views

Author

Giovanni Teofilatto, Apr 02 2005

Keywords

Comments

Primes of the form 6 + A111192(i). - R. J. Mathar, Nov 26 2008
All numbers in this sequence are of the form 12n + 1. Also, as one would expect from a random distribution of sexy prime pairs, with the exception of 61, in decimal two thirds of these numbers end in 3, and the other third end in 7. - Daniel Mondot, Apr 29 2024

Crossrefs

Extensions

Extended by R. J. Mathar, Nov 26 2008

A104228 Primes one larger than the sum over a sexy prime pair.

Original entry on oeis.org

17, 29, 41, 53, 89, 101, 113, 173, 269, 353, 389, 461, 509, 521, 701, 773, 929, 1013, 1181, 1193, 1289, 1301, 1361, 1721, 1889, 1901, 1949, 2213, 2381, 2441, 2609, 2729, 2741, 2861, 2969, 3209, 3221, 3821, 4001, 4133, 4421, 4481, 4673, 4793, 4889, 5381, 5393, 5801, 5813, 6173, 6653, 7349, 7529
Offset: 1

Views

Author

Giovanni Teofilatto, Apr 02 2005

Keywords

Comments

Primes of the form A023201(i)+A046117(i)+1 - R. J. Mathar, Nov 26 2008

Examples

			17=5+11+1 is prime and one larger than the sum 5+11 over the first sexy prime pair. - _R. J. Mathar_, Nov 26 2008
		

Crossrefs

Extensions

Inserted 89 and extended beyond a(8). - R. J. Mathar, Nov 26 2008

A104047 Primes p equal to the sum of two successive sexy primes - 1 such that p - 6 is also prime.

Original entry on oeis.org

19, 67, 79, 199, 547, 619, 739, 1459, 1759, 3319, 3739, 4027, 4567, 5107, 5419, 6367, 7219, 8719, 9187, 9907, 10459, 10867, 11119, 12547, 13099, 14827, 15739, 16927, 17047, 18307, 21319, 25939, 27259, 27367, 31327, 33967, 37579, 38839, 38959
Offset: 1

Views

Author

Giovanni Teofilatto, Mar 31 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Select[2#+5&/@Select[Prime[Range[4200]],PrimeQ[#+6]&],And@@PrimeQ[ {#,#-6}]&] (* Harvey P. Dale, Feb 28 2012 *)

Formula

A104227 INTERSECT A046117. [From R. J. Mathar, Nov 26 2008]

Extensions

23 and 29 removed, extended by R. J. Mathar, Nov 26 2008

A375091 First element p of sexy prime pairs (p,p+6) whose concatenation is also prime.

Original entry on oeis.org

11, 13, 17, 31, 83, 97, 101, 151, 157, 167, 223, 227, 233, 251, 257, 263, 271, 331, 353, 373, 433, 461, 541, 601, 653, 677, 727, 821, 823, 877, 941, 971, 1013, 1033, 1181, 1187, 1223, 1367, 1447, 1453, 1657, 1693, 1741, 1861, 1973, 1993, 1997, 2207, 2281, 2333, 2393, 2441
Offset: 1

Views

Author

James S. DeArmon, Jul 29 2024

Keywords

Examples

			11 is the first term, since (11,17) are sexy primes and 1117 is also prime.
The second term is 13, since 1319 is prime.
		

Crossrefs

Intersection of A023201 and A032621.

Programs

  • Maple
    q:= p-> andmap(isprime, [p, p+6, parse(cat(p, p+6))]):
    select(q, [$2..3000])[];  # Alois P. Heinz, Aug 02 2024
  • Mathematica
    Select[Prime[Range[370]], PrimeQ[#+6] && PrimeQ[FromDigits[Join[IntegerDigits[#], IntegerDigits[#+6]]]] &] (* Stefano Spezia, Aug 03 2024 *)
  • PARI
    isp(p) = isprime(p+6) && isprime(eval(concat(Str(p), Str(p+6))))
    select(isp, primes(100)) \\ Michel Marcus, Aug 02 2024
  • Python
    from sympy import isprime
    def ok(n): return isprime(n) and isprime(n+6) and isprime(int(str(n)+str(n+6)))
    print([k for k in range(2500) if ok(k)]) # Michael S. Branicky, Aug 01 2024
    
Showing 1-4 of 4 results.