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 1-4 of 4 results.

A271443 Earliest start of a run of n numbers divisible by a cube larger than one.

Original entry on oeis.org

8, 80, 1375, 22624, 18035622, 4379776620, 1204244328624, 2604639091138248, 2604639091138248
Offset: 1

Views

Author

Giovanni Resta, Apr 23 2016

Keywords

Comments

a(5)-a(7) were found by Donovan Johnson.

Examples

			a(9) = 2604639091138248 and the following 8 numbers are divisible by 2^3, 11^3, 5^3, 17^3, 7^3, 13^3, 3^3, 19^3, and 2^4, respectively.
		

Crossrefs

Programs

  • Mathematica
    a[n_] := Block[{k=1, c=0}, While[ c
    				

A271444 Smallest of 4 consecutive numbers each divisible by a cube greater than one.

Original entry on oeis.org

22624, 355374, 885624, 912247, 1558248, 1642624, 1728375, 1761991, 2068373, 2485375, 2948373, 2987872, 3072248, 3073623, 3243750, 3571749, 3744872, 3772248, 3916374, 4231248, 4442877, 4503247, 4730373, 4757750, 5301125, 5344623, 5516125, 5812477, 6017247
Offset: 1

Views

Author

Giovanni Resta, Apr 26 2016

Keywords

Examples

			a(1)=22624 is the smallest cubeful number followed by other 3 cubeful numbers. They are divisible by 2^5, 5^3, 3^3, and 11^3, respectively.
		

Crossrefs

Programs

  • Mathematica
    cubQ[n_] := Max[Last /@ FactorInteger[n]] > 2; Select[Range[10^6], cubQ[#] && cubQ[# + 1] && cubQ[# + 2] && cubQ[# + 3] &]
    SequencePosition[Table[If[AnyTrue[Rest[Divisors[n]],IntegerQ[CubeRoot[#]]&],1,0],{n,61*10^5}],{1,1,1,1}][[;;,1]] (* Harvey P. Dale, Jan 05 2025 *)

Extensions

Definition clarified by Harvey P. Dale, Jan 05 2025

A271446 Smallest of 6 consecutive numbers each divisible by a cube.

Original entry on oeis.org

4379776620, 6329354875, 16620507123, 54089484125, 55072893248, 66519175371, 68769514373, 80566783622, 87372290871, 91351389622, 99156598496, 105748687372, 112806598372, 114265205871, 117243671750, 148257477247, 155970667499, 174404710246, 177398391245
Offset: 1

Views

Author

Giovanni Resta, Apr 26 2016

Keywords

Examples

			a(1) = 4379776620 is the smallest cubeful number followed by other 5 cubeful numbers. They are divisible by 29^3, 11^3, 13^3, 3^3, 2^4, and 5^3, respectively.
		

Crossrefs

A271447 Smallest of 7 consecutive numbers each divisible by a cube.

Original entry on oeis.org

1204244328624, 4224987665871, 17911333617875, 18105599700248, 20656510708125, 20917131156124, 21707874550623, 30199064929748, 30517770625623, 32526295907749, 43865182834744, 47130022943124, 48617303189245, 50499660546373, 53555917697500, 53971309892123
Offset: 1

Views

Author

Giovanni Resta, Apr 26 2016

Keywords

Examples

			a(1) = 1204244328624 is the smallest cubeful number followed by other 4 cubeful numbers. They are divisible by 2^4, 5^3, 19^3, 3^3, 11^4, 37^3, and 7^3, respectively.
		

Crossrefs

Showing 1-4 of 4 results.