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.

Previous Showing 11-20 of 59 results. Next

A247466 Numbers n such that n!3 - 3^6 is prime.

Original entry on oeis.org

11, 26, 37, 38, 40, 41, 62, 131, 211, 212, 251, 272, 284, 383, 427, 538, 590, 860, 1087, 1280, 1826, 1835, 1895, 2276, 2524, 2872, 3769, 3878, 4334, 5704, 14332, 23386, 42694
Offset: 1

Views

Author

Robert Price, Sep 17 2014

Keywords

Comments

Large terms correspond to probable primes.
a(34) > 50000.

Examples

			11!3-729 = 11*8*5*2-729= 151 is prime, so 11 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] - 729], AppendTo[lst, n]], {n, 100}];lst

A247467 Numbers n such that n!3 + 3^6 is prime.

Original entry on oeis.org

4, 5, 7, 8, 10, 11, 14, 17, 35, 41, 50, 59, 89, 136, 164, 205, 224, 283, 763, 1034, 1253, 1630, 1820, 3199, 3800, 5080, 6124, 17306, 17398, 20768, 34033, 43607
Offset: 1

Views

Author

Robert Price, Sep 17 2014

Keywords

Comments

Large terms correspond to probable primes.
a(33) > 50000.

Examples

			11!3+729 = 11*8*5*2+729 = 1609 is prime, so 11 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 729], AppendTo[lst, n]], {n, 100}];lst

A247865 Numbers n such that n!3 + 3^2 is prime.

Original entry on oeis.org

2, 4, 5, 7, 8, 14, 17, 19, 22, 23, 26, 34, 46, 59, 70, 86, 100, 101, 118, 148, 151, 160, 200, 281, 317, 343, 682, 842, 853, 871, 1244, 1988, 2170, 2389, 2728, 3049, 3661, 4678, 9169, 12767, 16072, 19808, 20710, 33142, 33442
Offset: 1

Views

Author

Robert Price, Sep 25 2014

Keywords

Comments

Large terms correspond to probable primes.
a(46) > 50000.

Examples

			8!3+9 = 8*5*2+9= 89 is prime, so 8 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 9], AppendTo[lst, n]], {n, 100}];lst

A247866 Numbers k such that k!3 + 3^4 is prime.

Original entry on oeis.org

2, 7, 14, 16, 22, 23, 26, 40, 43, 47, 58, 62, 70, 107, 265, 292, 439, 874, 982, 1063, 1150, 2506, 3578, 3775, 7679, 10024, 42625, 46714
Offset: 1

Views

Author

Robert Price, Sep 25 2014

Keywords

Comments

Large terms correspond to probable primes.
a(29) > 50000.

Examples

			7!3 + 81 = 7*4*1 + 81 = 109 is prime, so 7 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 81], AppendTo[lst, n]], {n, 100}];lst

A247868 Numbers n such that n!3 + 3^5 is prime, where n!3 = n!!! is a triple factorial number (A007661).

Original entry on oeis.org

7, 10, 11, 22, 23, 25, 44, 46, 47, 50, 53, 55, 89, 122, 214, 410, 427, 526, 539, 575, 1369, 1370, 2291, 4999, 5374, 7202, 7375, 7823, 8921, 9764, 22967, 25507, 44117
Offset: 1

Views

Author

Robert Price, Sep 25 2014

Keywords

Comments

Large terms correspond to probable primes.
a(34) > 50000.

Examples

			10!3+243 = 10*7*4*1+243= 523 is prime, so 10 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 243], AppendTo[lst, n]], {n, 100}];lst

A247886 Numbers n such that n!3 + 3^3 is prime.

Original entry on oeis.org

2, 4, 5, 8, 10, 11, 14, 20, 23, 32, 34, 46, 47, 62, 136, 179, 208, 209, 229, 311, 340, 406, 692, 1235, 1349, 2558, 2651, 2873, 3794, 7417, 8647, 8695, 10004, 13595, 18658, 21427, 23120, 43316
Offset: 1

Views

Author

Robert Price, Sep 25 2014

Keywords

Comments

Large terms correspond to probable primes.
a(39) > 50000.

Examples

			10!3+27 = 10*7*4*1+27= 307 is prime, so 10 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 27], AppendTo[lst, n]], {n, 100}];lst

A249400 Numbers n such that n!3 + 3 is prime, where n!3 = n!!! is a triple factorial number (A007661).

Original entry on oeis.org

2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 19, 20, 26, 28, 29, 32, 41, 56, 61, 77, 100, 169, 181, 205, 338, 347, 955, 1952, 2197, 2428, 2960, 3430, 4618, 7478, 8209, 8422, 9235, 11107, 13481, 18194, 19229, 29854, 46532
Offset: 1

Views

Author

Robert Price, Oct 27 2014

Keywords

Comments

Large terms correspond to probable primes.
a(44) > 50000.

Examples

			11!3+3 = 11*8*5*2+3 = 883 is prime, so 11 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
lst={};Do[If[PrimeQ[MultiFactorial[n, 3] + 3], AppendTo[lst, n]], {n, 100}];lst

A261344 Numbers n such that n!3 - 3^8 is prime, where n!3 = n!!! is a triple factorial number (A007661).

Original entry on oeis.org

16, 17, 20, 25, 26, 35, 37, 47, 88, 94, 125, 127, 134, 326, 328, 368, 398, 425, 698, 700, 734, 1303, 1427, 2011, 2542, 2699, 3938, 4214, 5137, 6314, 8669, 9041, 12494, 13520, 14609, 23732, 41399, 43867, 49471
Offset: 1

Views

Author

Robert Price, Nov 18 2015

Keywords

Comments

n=5 and n=8 produce values (-6551 and -6481) whose absolute value is a prime.
Corresponding primes are: 51679, 202879, 4182239, 608601439, 2504895839, ...
a(40) > 50000.
Terms > 26 correspond to probable primes.

Examples

			16!3 - 3^8 = 16*13*10*7*4*1 - 6561 = 51679 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, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 3] - 3^8] &]
Select[Range[14,800],PrimeQ[Times@@Range[#,1,-3]-6561]&] (* The program generates the first 21 terms of the sequence. To generate more, increase the Range constant. *) (* Harvey P. Dale, Apr 27 2022 *)
  • PARI
    for(n=1, 1e3, if(ispseudoprime(prod(i=0, floor((n-1)/3), n-3*i) - 3^8), print1(n, ", "))) \\ Altug Alkan, Nov 18 2015

A264867 Numbers n such that n!3 + 3^8 is prime, where n!3 = n!!! is a triple factorial number (A007661).

Original entry on oeis.org

2, 5, 10, 26, 34, 35, 37, 59, 68, 76, 104, 106, 188, 193, 242, 278, 287, 290, 572, 772, 773, 1304, 2384, 2716, 3715, 4562, 6706, 11489, 11711, 21602, 24295, 24775, 27224, 29935, 37856
Offset: 1

Views

Author

Robert Price, Nov 26 2015

Keywords

Comments

Corresponding primes are 6563, 6571, 6841, 2504908961, 17961239302561, 81359229958561, 664565853958561, ...
Terms > 68 correspond to probable primes.
a(36) > 50000.

Examples

			10!3 + 3^4 = 10*7*4*1 + 6561 = 6841 is prime, so 10 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 3] + 3^8] &]
Select[Range[800],PrimeQ[6561+Times@@Range[#,1,-3]]&] (* Harvey P. Dale, Mar 08 2023 *)
  • PARI
    is(n)=ispseudoprime(n!!! + 3^8) \\ Anders Hellström, Nov 27 2015
  • PARI
    tf(n) = prod(i=0,(n-1)\3, n-3*i);
for(n=1, 1e4, if(ispseudoprime(tf(n) + 3^8), print1(n , ", "))) \\  Altug Alkan, Dec 03 2015

A265378 Numbers n such that n!3 + 3^9 is prime, where n!3 = n!!! is a triple factorial number (A007661).

Original entry on oeis.org

4, 8, 10, 11, 14, 17, 20, 22, 29, 32, 44, 56, 61, 173, 202, 211, 215, 241, 388, 410, 416, 569, 583, 680, 823, 964, 1271, 1732, 2309, 2335, 2404, 2765, 3019, 3047, 4670, 5209, 6320, 6817, 7531, 9923, 11243, 14912, 17969, 21193, 28940
Offset: 1

Views

Author

Robert Price, Dec 07 2015

Keywords

Comments

Corresponding primes are: 19687, 19763, 19963, 20563, 32003, 229123, 4208483, 24364003, 72642189283, ...
a(46) > 50000.
Terms > 61 correspond to probable primes.

Examples

			11!3 + 3^9 = 11*8*5*2 + 19683 = 20563 is prime, so 11 is in the sequence.

Links

Crossrefs

Cf. A007661, A037082, A084438, A123910, A242994, A261145, A265200.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n < 1, 1, If[n < k + 1, n, n*MultiFactorial[n - k, k]]];
Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 3] + 3^9] &]
  • PARI
    tf(n) = prod(i=0, (n-1)\3, n-3*i);
for(n=1, 1e4, if(ispseudoprime(tf(n) + 3^9), print1(n , ", "))) \\ Altug Alkan, Dec 07 2015
Previous Showing 11-20 of 59 results. Next

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