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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A288891 Primes of the form k!6+2, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

3, 5, 7, 29, 937, 229637, 13299311027, 678264862277, 2229272062327, 8260613413473469333910627, 204676724960380351177777255683652821505300292407056383439453127, 359539042675600162641430486036393282148945045174959856388131309765627
Offset: 1

Views

Author

Robert Price, Jun 18 2017

Keywords

Links

Crossrefs

Cf. A287207.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 6] + 2, {i, 0, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n,1,-6]+2,{n,250}],PrimeQ] (* Harvey P. Dale, Nov 20 2024 *)

A289547 Numbers k such that k!6 - 4 is prime, where k!6 is the sextuple factorial number (A085158 ).

Original entry on oeis.org

6, 7, 9, 15, 21, 27, 29, 321, 327, 333, 567, 1025, 4263, 4365, 5175, 5655, 9221, 9327, 9681, 19685, 24777, 57869, 58737
Offset: 1

Views

Author

Robert Price, Jul 07 2017

Keywords

Comments

Corresponding primes are: 2, 3, 23, 401, 8501, 229631, 623641, ...
a(24) > 10^5.
Terms > 29 correspond to probable primes.

Examples

			15!6 - 4 = 15*9*3 - 4 = 401 is prime, so 15 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[4, 50000], PrimeQ[MultiFactorial[#, 6] - 4] &]

Extensions

a(22)-a(23) from Robert Price, Aug 03 2018

A289549 Primes of the form k!6-3, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

2, 3, 13, 37, 73569236156415997, 2076797833465298943997, 3445912395099815280639997, 337699414719781897502719997, 2406637297721880276844203212799997, 56505983376657530671203898929399315771217221372411818526783048069123288081453694320639999999999997
Offset: 1

Views

Author

Robert Price, Jul 07 2017

Keywords

Links

Crossrefs

Cf. A279646.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 6] - 3, {i, 3, 100}], PrimeQ[#]&]

A289550 Primes of the form k!6-4, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

2, 3, 23, 401, 8501, 229631, 623641
Offset: 1

Views

Author

Robert Price, Jul 07 2017

Keywords

Comments

The next term is too large to display.
The next term (a(8)) has 113 digits. - Harvey P. Dale, Dec 09 2020

Links

Crossrefs

Cf. A289547.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 6] - 4, {i, 4, 100}], PrimeQ[#]&]
Select[Table[Times@@Range[n,1,-6]-4,{n,3,100}],PrimeQ] (* Harvey P. Dale, Dec 09 2020 *)

A289685 Numbers k such that k!6 - 6 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

17, 19, 23, 31, 37, 47, 65, 151, 157, 251, 283, 371, 391, 635, 779, 799, 1517, 1799, 3355, 24619, 40375, 40793, 53135, 79427
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 929, 1723, 21499, 1339969, 49579069, 42061737019, ...
a(25) > 10^5.
Terms > 65 correspond to probable primes.

Examples

			17!6 - 6 = 17*11*5 - 6 = 929 is prime, so 17 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[6, 50000], PrimeQ[MultiFactorial[#, 6] - 6] &]

Extensions

a(23)-a(24) from Robert Price, Aug 03 2018

A289686 Numbers k such that k!6 - 8 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

9, 11, 13, 15, 19, 27, 35, 39, 45, 51, 83, 99, 105, 111, 121, 123, 127, 133, 175, 177, 213, 263, 277, 285, 339, 347, 543, 681, 743, 1069, 1965, 2379, 2613, 2629, 2911, 3767, 3879, 4789, 5493, 5819, 11559, 14555, 17831, 19705, 24867, 37535, 85089
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 19, 47, 83, 397, 1721, 229627, 21827567, ...
a(48) > 10^5.
Terms > 99 correspond to probable primes.

Examples

			19!6 - 8 = 19*13*7 - 8 = 1721 is prime, so 19 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[8, 50000], PrimeQ[MultiFactorial[#, 6] - 8] &]

Extensions

a(47) from Robert Price, Aug 03 2018

A289687 Numbers k such that k!6 - 9 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

8, 10, 16, 22, 26, 46, 52, 56, 70, 74, 286, 302, 308, 484, 698, 1100, 1226, 1528, 2486, 3796, 4256, 8524, 10688, 19424, 22226, 49346, 53746, 64178, 84304
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 7, 31, 631, 14071, 116471, 24663654391, 1282510028791, ...
a(30) > 10^5.
Terms > 46 correspond to probable primes.

Examples

			16!6 - 9 = 16*10*4 - 8 = 631 is prime, so 16 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[8, 50000], PrimeQ[MultiFactorial[#, 6] - 9] &]

Extensions

a(27)-a(29) from Robert Price, Aug 03 2018

A289688 Numbers k such that k!6 - 12 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

11, 13, 23, 29, 35, 37, 49, 95, 97, 101, 113, 133, 137, 361, 401, 701, 1027, 1331, 2087, 2743, 7781, 9391, 12787, 12797, 16123, 17317, 21701, 49657, 64661, 72149, 86413
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 43, 79, 21493, 623633, 21827563, 49579063, 104463111013, ...
a(32) > 10^5.
Terms > 49 correspond to probable primes.

Examples

			13!6 - 12 = 13*7*1 - 12 = 79 is prime, so 13 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[8, 50000], PrimeQ[MultiFactorial[#, 6] - 12] &]

Extensions

a(29)-a(31) from Robert Price, Aug 03 2018

A289689 Numbers k such that k!6 - 16 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

9, 15, 17, 65, 129, 135, 209, 225, 327, 357, 423, 1061, 1143, 3629, 4937, 6713, 33123, 79185, 88323, 89933
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 11, 389, 919, 8549258359016359, 17694587964658118355578965371540271859, ...
a(21) > 10^5.
Terms > 17 correspond to probable primes.

Examples

			17!6 - 16 = 17*11*5 - 16 = 919 is prime, so 17 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[6, 50000], PrimeQ[MultiFactorial[#, 6] - 16] &]

Extensions

a(18)-a(20) from Robert Price, Aug 03 2018

A289696 Numbers k such that k!6 - 18 is prime, where k!6 is the sextuple factorial number (A085158).

Original entry on oeis.org

11, 13, 23, 25, 35, 85, 89, 91, 103, 127, 161, 265, 295, 385, 605, 719, 913, 1379, 1423, 1481, 1603, 2129, 2603, 3893, 4739, 6461, 7249, 7549, 8149, 10633, 14447, 27463, 30323, 33991, 35821, 42221, 46525, 59057
Offset: 1

Views

Author

Robert Price, Jul 09 2017

Keywords

Comments

Corresponding primes are: 37, 73, 21487, 43207, 21827557, 11510631741140058401857, ...
a(39) > 10^5.
Terms > 35 correspond to probable primes.

Examples

			13!6 - 18 = 13*7 - 18 = 73 is prime, so 13 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
Select[Range[9, 50000], PrimeQ[MultiFactorial[#, 6] - 18] &]
Select[Range[11,60000],PrimeQ[Times@@Range[#,1,-6]-18]&] (* Harvey P. Dale, Aug 10 2019 *)

Extensions

a(38) from Robert Price, Aug 03 2018
Previous Showing 31-40 of 77 results. Next

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

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