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 39 results. Next

A139068 Primes of the form k!/9 + 1.

Original entry on oeis.org

4481, 611402462201343216650033936533361654773516861440000000001, 234195255375503079690400057633265510581087082006817356924774723468294901747510352675631491470712754833859385753600000000000000000001
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

For numbers k for which (9+k!)/9 is prime see A137390.

Links

Crossrefs

Cf. A020458, A007749, A082672, A089085, A089130, A117141, A137390, A139056, A139057, A139058, A139059, A139060, A139061, A139062, A139063, A139064, A139065, A139066, A137390, A139070, A139071, A139072, A139156.

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 9)/9], AppendTo[a, (n! + 9)/9]], {n, 1, 150}]; a
Select[Range[100]!/9+1,PrimeQ] (* Harvey P. Dale, Aug 17 2017 *)
  • PARI
    for(n=6,1e4,if(ispseudoprime(t=n!/9+1),print1(t", "))) \\ Charles R Greathouse IV, Jul 15 2011

Formula

a(n) = A139156(A137390(n)). - Amiram Eldar, Oct 14 2024

A139070 Primes of the form (10+k!)/10.

Original entry on oeis.org

13, 73, 3991681, 47900161, 130767436801, 2585201673888497664001, 40329146112660563558400001, 1376375309122634504631597958158090240000001, 11962222086548019456196316149565771506438373376000000001
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

For numbers k for which (10+k!)/10 is prime see A139071.

Links

Crossrefs

Cf. A020458, A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139062, A139063, A139064, A139065, A139066, A139068, A137390, A139071, A139072, A139157.

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 10)/10], AppendTo[a, (n! + 10)/10]], {n, 1, 50}]; a
Select[(Range[50]!+10)/10,PrimeQ] (* Harvey P. Dale, Sep 18 2013 *)
  • PARI
    for(k=5,1e3,if(ispseudoprime(t=k!/10+1),print1(t", "))) \\ Charles R Greathouse IV, Jul 15 2011

Formula

a(n) = A139157(A139071(n)). - Amiram Eldar, Oct 14 2024

A139075 Primes p arising in A139074.

Original entry on oeis.org

3, 2, 3, 31, 1009, 2, 5702401, 631
Offset: 1

Views

Author

Artur Jasinski, Apr 08 2008, Apr 21 2008

Keywords

Comments

a(23) = (23+1579!)/23. - Andrew V. Sutherland, Apr 11 2008.
Smallest mother factorial prime p of order n, i.e. smallest prime of the form (p!+n)/n where p is prime.
For smallest daughter factorial prime p of order n see A139074.
For smallest father factorial prime p of order n see A139207.
For smallest son factorial prime p of order n see A139206.
a(9)=26737!/9+1 is a 106758 digit (probable) prime. Easily calculated but too large to enter here a(10)=13, a(11)=566092801, a(12)=11. [Robert Price, Jan 19 2011]

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056-A139066, A020458, A139068, A137390, A139070-A139075, A136019, A136020, A136026, A136027.

Programs

  • Mathematica
    a = {}; Do[k = 1; While[ ! PrimeQ[(Prime[k]! + n)/n], k++ ]; AppendTo[a, Prime[(Prime[k]! + n)/n]], {n, 1, 8}]; a

A139061 Numbers n for which (4+n!)/4 is prime.

Original entry on oeis.org

4, 5, 6, 13, 21, 25, 32, 40, 61, 97, 147, 324, 325, 348, 369, 1290, 1342, 3167, 6612, 8176, 10990
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

For primes of the form (4+k!)/4, see A139060.
a(22) > 25000. - Robert Price, Jan 10 2017

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458, A139068, A137390, A139070, A139071, A139072.
Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 4)/4], AppendTo[a, n]], {n, 1, 500}]; a
Select[Range[500],PrimeQ[(4+#!)/4]&]  (* Harvey P. Dale, Mar 24 2011 *)
  • PARI
    for(n=4,1e3,if(ispseudoprime(n!/4+1),print1(n", "))) \\ Charles R Greathouse IV, Jul 15 2011

Extensions

More terms from Serge Batalov, Feb 18 2015
a(19) - a(21) from Robert Price, Jan 10 2017

A139063 Numbers k for which (6+k!)/6 is prime.

Original entry on oeis.org

3, 4, 10, 11, 13, 14, 17, 21, 82, 115, 165, 167, 173, 174, 208, 225, 380, 655, 1187, 2000, 2568, 3010, 4542, 8750, 12257, 12601, 24083
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

For primes of the form (6+k!)/6, see A139062.
a(28) > 25000. - Robert Price, Nov 20 2016

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458.
Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 6)/6], AppendTo[a, n]], {n, 1, 500}]; a
  • PARI
    for(k=3,1e3,if(ispseudoprime(k!/6+1),print1(k", "))) \\ Charles R Greathouse IV, Jul 15 2011

Extensions

a(18) and a(19) from Robert Israel, May 19 2014
More terms from Serge Batalov, Feb 18 2015
a(24)-a(27) from Robert Price, Nov 20 2016

A139065 Numbers k for which (7+k!)/7 is prime.

Original entry on oeis.org

11, 15, 16, 25, 35, 59, 64, 68, 82, 121, 149, 238, 584, 912, 3349, 4111, 4324, 15314, 19944, 20658, 22740, 23364
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

For primes of the form (7+k!)/7, see A139064.
a(23) > 25000. - Robert Price, Nov 20 2016

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458.
Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 7)/7], AppendTo[a, n]], {n, 1, 500}]; a
Select[Range[500],PrimeQ[(7+#!)/7]&] (* Harvey P. Dale, Sep 01 2014 *)
  • PARI
    for(k=7,1e3,if(ispseudoprime(k!/7+1),print1(k", "))) \\ Charles R Greathouse IV, Jul 15 2011

Extensions

More terms from Serge Batalov, Feb 18 2015
a(18)-a(22) from Robert Price, Nov 20 2016

A139157 a(n) = (n!+10)/10.

Original entry on oeis.org

13, 73, 505, 4033, 36289, 362881, 3991681, 47900161, 622702081, 8717829121, 130767436801, 2092278988801, 35568742809601, 640237370572801, 12164510040883201, 243290200817664001, 5109094217170944001
Offset: 5

Views

Author

Artur Jasinski, Apr 11 2008

Keywords

Links

Crossrefs

Cf. A007749, A020458, A082672, A089085, A089130, A117141, A139056-A139066, A139068, A137390, A139070-A139075, A139148-A139156, A139159, A139160, A139161, A139162.

Programs

  • Mathematica
    Table[(n! + 10)/10, {n, 5, 30}]
  • PARI
    for(n=5, 20, a=(n!+10)/10; print1(a, ", ")) \\ Felix Fröhlich, Jul 07 2014

Extensions

Name corrected by Amiram Eldar, Oct 14 2024

A139071 Numbers k for which (10+k!)/10 is prime.

Original entry on oeis.org

5, 6, 11, 12, 15, 23, 26, 37, 45, 108, 112, 129, 137, 148, 172, 248, 760, 807, 975, 1398, 5231, 8765, 24182
Offset: 1

Views

Author

Artur Jasinski, Apr 07 2008

Keywords

Comments

Primes of the form (10+k!)/10 see A139070.
a(24) > 25000. - Robert Price, Nov 08 2016

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458, A139068, A137390, A139070, A139071, A139072.
Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[(n! + 10)/10], AppendTo[a, n]], {n, 1, 500}]; a
  • PARI
    for(k=5,1e3,if(ispseudoprime(k!/10+1),print1(k", "))) \\ Charles R Greathouse IV, Jul 15 2011

Extensions

More terms from Serge Batalov, Feb 18 2015
a(22)-a(23) from Robert Price, Nov 08 2016

A139148 Smallest positive integer of the form (m!+n)/n.

Original entry on oeis.org

2, 2, 3, 7, 25, 2, 721, 4, 81, 13, 3628801, 3, 479001601, 361, 9, 46, 20922789888001, 41, 6402373705728001, 7, 241, 1814401, 1124000727777607680001, 2, 145153, 239500801, 13441, 181, 304888344611713860501504000001, 5
Offset: 1

Views

Author

Artur Jasinski, Apr 11 2008

Keywords

Links

Crossrefs

Cf. A002034, A007672, A082672, A089085, A089130, A117141, A007749, A139056-A139066, A020458, A139068, A137390, A139070-A139075, A139148-A139157, A139159, A139160-A139162.

Programs

  • Mathematica
    a = {}; Do[m = 1; While[ ! IntegerQ[m!/n], m++ ]; AppendTo[a, (m! + n)/n], {n, 1, 50}]; a

Formula

a(n) = (n + (A002034(n))!)/n.
a(n) = A007672(n) + 1. - Charles R Greathouse IV, Dec 09 2014

A139160 a(n)=(prime(n)!+2)/2.

Original entry on oeis.org

2, 4, 61, 2521, 19958401, 3113510401, 177843714048001, 60822550204416001, 12926008369442488320001, 4420880996869850977271808000001, 4111419327088961408862781440000001
Offset: 1

Views

Author

Artur Jasinski, Apr 11 2008

Keywords

Comments

For numbers of the form (p(n)!+1)/1 see A139159
For numbers of the form (p(n)!+2)/2 see A139160
For numbers of the form (p(n)!+3)/3 see A139161
For numbers of the form (p(n)!+4)/4 see A139162
For numbers of the form (p(n)!+5)/5 see A139163
For numbers of the form (p(n)!+6)/6 see A139164
For numbers of the form (p(n)!+7)/7 see A139165
For numbers of the form (p(n)!+8)/8 see A139166
For numbers of the form (p(n)!+9)/9 see A139089
For numbers of the form (p(n)!+10)/10 see A139168
For offsets for above sequences see A139169
For smallest integers of the form (p(m)!+n)/n see A139170

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056-A139066, A020458, A139068, A137390, A139070-A139075, A139148-A139157, A139159, A139160-A139166, A139089, A139168-A139170.

Programs

  • Mathematica
    Table[(Prime[n]! + 2)/2, {n, 1, 30}]
  • PARI
    a(n)=prime(n)!/2 + 1 \\ Charles R Greathouse IV, Apr 29 2015
Showing 1-10 of 39 results. Next

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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