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 1-3 of 3 results.

A083790 Smallest start of n consecutive numbers with distinct prime signatures.

Original entry on oeis.org

1, 1, 4, 6, 8, 23, 24, 1804, 1968, 8375, 53750, 243864, 639324, 41381620, 102621343, 7802708736, 7802708736, 178874468615, 1133934949368
Offset: 1

Views

Author

Amarnath Murthy, May 07 2003

Keywords

Comments

a(16) > 750000000. - Ray Chandler, Aug 21 2003
a(16) > 6.646*10^9. - David Wasserman, Jan 08 2006
a(18) > 10^11. - Donovan Johnson, Oct 24 2009
a(20) > 10^13. - Giovanni Resta, Jul 13 2015

Crossrefs

A124058 gives another version of the same sequence.
First column of A083788.

Extensions

Corrected and extended by Ray Chandler, Aug 17 2003
More terms from Ray Chandler, Aug 21 2003
a(16)-a(17) from Donovan Johnson, Oct 24 2009
a(18)-a(19) from Giovanni Resta, Jul 13 2015
New name from Jon E. Schoenfield, Nov 17 2022

A083788 Triangle read by rows, in which n-th row contains smallest set of n consecutive numbers with distinct prime signatures.

Original entry on oeis.org

1, 1, 2, 4, 5, 6, 6, 7, 8, 9, 8, 9, 10, 11, 12, 23, 24, 25, 26, 27, 28, 24, 25, 26, 27, 28, 29, 30, 1804, 1805, 1806, 1807, 1808, 1809, 1810, 1811, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 8375, 8376, 8377, 8378, 8379, 8380, 8381, 8382, 8383, 8384
Offset: 1

Views

Author

Amarnath Murthy, May 07 2003

Keywords

Comments

Question: Given n with a prime signature say p^a*q^b*r^c... find a tight upper limit m such that there exists a number k, n < k < m with the same prime signature.

Examples

			1;
1,2;
4,5,6;
6,7,8,9;
8,9,10,11,12;
23,24,25,26,27,28;
24,25,26,27,28,29,30;
1804,1805,1806,1807,1808,1809,1810,1811;
1968,1969,1970,1971,1972,1973,1974,1975,1976;
8375,8376,8377,8378,8379,8380,8381,8382,8383,8384;
53750,53751,53752,53753,53754,53755,53756,53757,53758,53759,53760;
...
Row 4 contains 6,7,8 and 9 with prime signatures p*q,p,p^3,p^2 respectively.
		

Crossrefs

Extensions

Corrected and extended by Ray Chandler, Aug 17 2003

A083789 Diagonal of A083788.

Original entry on oeis.org

1, 2, 6, 9, 12, 28, 30, 1811, 1976, 8384, 53760, 243875, 639336, 41381633, 102621357, 7802708751, 7802708752, 178874468632, 1133934949386
Offset: 1

Views

Author

Amarnath Murthy, May 07 2003

Keywords

Comments

a(16) > 750000000. - Ray Chandler, Aug 21 2003
a(18) > 10^11. [Donovan Johnson, Oct 24 2009]
a(20) > 10^13. - Giovanni Resta, Jul 13 2015

Crossrefs

Extensions

Corrected and extended by Ray Chandler, Aug 17 2003
More terms from Ray Chandler, Aug 21 2003
a(16)-a(17) from Donovan Johnson, Oct 24 2009
a(18)-a(19) from Giovanni Resta, Jul 13 2015
Showing 1-3 of 3 results.