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 1-10 of 13 results. Next

A132903 Numbers formed by concatenating 3 consecutive prime numbers.

Original entry on oeis.org

235, 357, 5711, 71113, 111317, 131719, 171923, 192329, 232931, 293137, 313741, 374143, 414347, 434753, 475359, 535961, 596167, 616771, 677173, 717379, 737983, 798389, 838997, 8997101, 97101103, 101103107, 103107109, 107109113, 109113127
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Examples

			Prime numbers.
2
3
5 -----------> a(1) = 235
7 -----------> a(2) = 357
11 ----------> a(3) = 5711

Links

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A091762.

Programs

  • Mathematica
    FromDigits[Flatten[IntegerDigits[#]]]&/@Partition[Prime[Range[40]],3,1] (* Harvey P. Dale, Jan 03 2021 *)

A007797 List of pairs of primes in reverse order.

Original entry on oeis.org

32, 75, 1311, 1917, 2923, 3731, 4341, 5347, 6159, 7167, 7973, 8983, 10197, 107103, 113109, 131127, 139137, 151149, 163157, 173167, 181179, 193191, 199197, 223211, 229227, 239233, 251241, 263257, 271269, 281277, 293283, 311307, 317313, 337331, 349347, 359353
Offset: 1

Views

Author

William B. Moore (bmoore(AT)artemis.ess.ucla.edu)

Keywords

Links

Crossrefs

Cf. A007795.

Programs

  • Magma
    [Seqint(Intseq(NthPrime(n)) cat Intseq(NthPrime(n+1))): n in [1..86 by 2]]; // Vincenzo Librandi, Jan 05 2018
  • Mathematica
    FromDigits/@(Flatten[IntegerDigits/@Reverse[#]]&/@Partition[Prime[Range[2*40]], 2]) (* Vincenzo Librandi, Jan 05 2018 *)

A132901 Numbers formed by concatenating 11 consecutive prime numbers.

Original entry on oeis.org

235711131719232931, 3571113171923293137, 57111317192329313741, 711131719232931374143, 1113171923293137414347, 1317192329313741434753, 1719232931374143475359, 1923293137414347535961, 2329313741434753596167
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Links

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

A132905 Numbers formed by concatenating 5 consecutive prime numbers.

Original entry on oeis.org

235711, 3571113, 57111317, 711131719, 1113171923, 1317192329, 1719232931, 1923293137, 2329313741, 2931374143, 3137414347, 3741434753, 4143475359, 4347535961, 4753596167, 5359616771, 5961677173, 6167717379, 6771737983
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

A153353 List of pairs of concatenated adjacent primes [p(n),p(n+1)] such that the concatenation is divisible by n.

Original entry on oeis.org

23, 57, 127131, 937941, 2087320879, 6557965581, 925039925051, 14073611407383, 89811798981191, 94647139464723, 1553629915536303, 122504623122504633, 200602291200602313, 495401873495401911, 133201458751133201458773
Offset: 1

Views

Author

Gil Broussard, Dec 24 2008

Keywords

Comments

The corresponding values of n are listed in A125085.
Subset of A045533. [R. J. Mathar, Jan 03 2009]

Examples

			23 is a term because 2 and 3 are adjacent primes and 23 is divisible by 1 (the position of 2 in the sequence of primes).
127131 is a term because 127 and 131 are adjacent primes and 127131 is divisible by 31 (the position of 127 in the sequence of primes).

Crossrefs

Cf. A007795, A045533, A095958.
Cf. A000040.

Programs

  • Maple
    A055642 := proc(n) max(1,ilog10(n)+1) ; end: cat2 := proc(a,b) a*10^A055642(b)+b ; end: A045533 := proc(n) cat2(ithprime(n),ithprime(n+1)) ; end: for n from 1 to 800000 do if A045533(n) mod n = 0 then printf("%d,",A045533(n)) ; fi; od: # R. J. Mathar, Jan 03 2009
  • Mathematica
    p = q = 2; c = 0; lst = {}; Do[c++; q = NextPrime@q; r = FromDigits@ Flatten[{IntegerDigits@ p, IntegerDigits@ q}]; If[Mod[r, c] == 0, AppendTo[lst, r]; Print[{c, r}]]; c++; q = NextPrime@ q; p = q, {n, 174254000}]; lst (* Robert G. Wilson v, Jan 23 2009 *)

Extensions

3 more terms from R. J. Mathar, Jan 03 2009
a(9)-a(14) from Robert G. Wilson v, Jan 23 2009
a(15) from Donovan Johnson, Aug 08 2010

A132902 Numbers formed by concatenating 12 consecutive prime numbers.

Original entry on oeis.org

23571113171923293137, 357111317192329313741, 5711131719232931374143, 71113171923293137414347, 111317192329313741434753, 131719232931374143475359, 171923293137414347535961
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

Programs

  • Mathematica
    FromDigits[Flatten[IntegerDigits/@#]]&/@Partition[Prime[Range[20]],12,1] (* Harvey P. Dale, May 27 2017 *)

A132904 Numbers formed by concatenating 4 consecutive prime numbers.

Original entry on oeis.org

2357, 35711, 571113, 7111317, 11131719, 13171923, 17192329, 19232931, 23293137, 29313741, 31374143, 37414347, 41434753, 43475359, 47535961, 53596167, 59616771, 61677173, 67717379, 71737983, 73798389, 79838997, 838997101
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Links

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

Formula

Prime numbers. 2 3 5 7 --------------> a(1) = 2357 11 -------------> a(2) = 35711

A132906 Numbers formed by concatenating 6 consecutive prime numbers.

Original entry on oeis.org

23571113, 357111317, 5711131719, 71113171923, 111317192329, 131719232931, 171923293137, 192329313741, 232931374143, 293137414347, 313741434753, 374143475359, 414347535961, 434753596167, 475359616771, 535961677173
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

A132907 Numbers formed by concatenating 7 consecutive prime numbers.

Original entry on oeis.org

2357111317, 35711131719, 571113171923, 7111317192329, 11131719232931, 13171923293137, 17192329313741, 19232931374143, 23293137414347, 29313741434753, 31374143475359, 37414347535961, 41434753596167
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Crossrefs

Prime numbers: A000040. Cf. A007795, A045533, A059932, A091762.

A132908 Numbers formed by concatenating 8 consecutive prime numbers.

Original entry on oeis.org

235711131719, 3571113171923, 57111317192329, 711131719232931, 1113171923293137, 1317192329313741, 1719232931374143, 1923293137414347, 2329313741434753, 2931374143475359, 3137414347535961, 3741434753596167
Offset: 1

Views

Author

Omar E. Pol, Sep 04 2007

Keywords

Crossrefs

Cf. A000040, A007795, A045533, A059932, A091762.

Programs

  • Mathematica
    FromDigits/@(Flatten[IntegerDigits/@#]&/@(Partition[Prime[Range[20]],8,1])) (* Harvey P. Dale, Mar 06 2011 *)
Showing 1-10 of 13 results. Next

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