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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A289817 Primes of the form k!3-9, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

19, 71, 271, 3631, 58231, 209431, 4188791, 96342391, 17041023991, 72642169591, 2324549427191, 1143053268797439991, 52580450364682239991, 262134882788466687991, 694657439389436723199991, 38900816605808456499199991, 2295148179742698933452799991
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A243078.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 9, {i, 5, 100}], PrimeQ[#]&]

A289818 Primes of the form k!3-27, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

53, 853, 3613, 24344293, 72642169573, 2576442067869429759973, 38900816605808456499199973, 26070192823309041523916799973, 17978533302590087193373917833428087202627190783999999973
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A247463.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 27, {i, 7, 100}], PrimeQ[#]&]
    Select[Table[Times@@Range[n,1,-3]-27,{n,7,150}],PrimeQ] (* Harvey P. Dale, Mar 08 2020 *)

A289819 Primes of the form k!3-81, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

199, 3559, 12239, 209359, 4188719, 2504902319, 72642169519, 528271743919, 2324549427119, 13106744139423334399919, 2295148179742698933452799919, 254451773522587035734629406212095999919, 281238294844900882734503454910185471999919
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A247464.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 81, {i, 9, 100}], PrimeQ[#]&]
    Select[Table[Times@@Range[n,1,-3],{n,8,150}]-81,PrimeQ] (* Harvey P. Dale, Nov 14 2022 *)

A289820 Primes of the form k!3-243, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

37, 1106317, 17041023757, 13106744139423334399757, 111788986826349170054555238399757, 254451773522587035734629406212095999757, 12931890526958090978845347074978621685759999757, 23265085063150097152411131624511949388385310979653631999999757
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A247465.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 243, {i, 10, 100}], PrimeQ[#]&]
    Select[Table[Times@@Range[n,1,-3]-243,{n,10,150}],PrimeQ] (* Harvey P. Dale, Jan 01 2025 *)

A289821 Primes of the form k!3-729, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

151, 2504901671, 664565853951271, 3091650738175271, 26582634158079271, 126757680265215271, 142299187144047333874073599271, 546216992715109618958387336810111087297326406997164406744285183999999999271
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A247466.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 729, {i, 11, 100}], PrimeQ[#]&]

A289822 Primes of the form k!3-2187, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

1453, 10133, 56053, 1104373, 24342133, 96340213, 2504900213, 3091650738173813, 1668492340691778657530675197813, 116346745870073113470947277571643877742200278220799997813, 10027451552263982384838074729160019340604318179653944179011587407871999999997813
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A267382.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 2187, {i, 13, 100}], PrimeQ[#]&]
    Select[Table[Times@@Range[n,1,-3]-2187,{n,13,200}],PrimeQ] (* Harvey P. Dale, Jul 15 2023 *)

A289823 Primes of the form k!3-6561, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

51679, 202879, 4182239, 608601439, 2504895839, 81359229945439, 664565853945439, 262134882788466681439, 2103662445439858602854085842728187330559993439, 17994728558292550488813850298696914425610239993439
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Cf. A261344.

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 6561, {i, 14, 100}], PrimeQ[#]&]

A289824 Primes of the form k!3 - 19683, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

38557, 189757, 17961239276317, 3091650738156317, 2576442067869429740317, 142299187144047333874073580317, 3304568487306325139410771509247980317, 1745488670154377397414943478973600699284193279980317, 32574963783105296932155733349839640225269943165384327692287999999980317
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 19683, {i, 15, 100}], PrimeQ[#]&]
    Select[Table[Times@@Range[n,1,-3]-19683,{n,15,100}],PrimeQ] (* Harvey P. Dale, Dec 14 2019 *)

Formula

a(n) = A007661(A267029(n)) - 19683. - Elmo R. Oliveira, Feb 25 2025

A289825 Primes of the form k!3 - 59049, where k!3 is the triple factorial number (A007661).

Original entry on oeis.org

1047511, 4129751, 24285271, 2504843351, 126757680265156951, 7368624314106569113540951, 38900816605808456499140951, 663800167477016615356604425212847831700575205814331164458540403251687739883519999999940951
Offset: 1

Views

Author

Robert Price, Jul 12 2017

Keywords

Crossrefs

Programs

  • Mathematica
    MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
    Select[Table[MultiFactorial[i, 3] - 59049, {i, 17, 100}], PrimeQ[#]&]

Formula

a(n) = A007661(A265201(n)) - 59049. - Elmo R. Oliveira, Feb 25 2025

A114778 Cumulative product of triple factorial A007661.

Original entry on oeis.org

1, 1, 2, 6, 24, 240, 4320, 120960, 9676800, 1567641600, 438939648000, 386266890240000, 750902834626560000, 2733286318040678400000, 33674087438261157888000000, 981936389699695364014080000000
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Comments

This is the product analog of what for sums is A114347.

Examples

			a(10) = 1!!! * 2!!! * 3!!! * 4!!! * 5!!! * 6!!! * 7!!! * 8!!! * 9!!! * 10!!!
= 1 * 2 * 3 * 4 * 10 * 18 * 28 * 80 * 162 * 280 = 438939648000 = 2^15 * 3^7 * 5^3 * 7^2.
		

Crossrefs

Formula

a(n) = Product_{j=0..n} j!!!. a(n) = Product_{j=0..n} A007661(j). a(n) = n!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2. a(n) = n*(n-3)!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2 and n >= 3.
Previous Showing 31-40 of 118 results. Next