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 1-5 of 5 results.

A077172 Triangle formed by grouping the natural numbers so that the n-th row contains n numbers whose product has exactly n distinct prime divisors.

Original entry on oeis.org

2, 1, 6, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 16, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 48, 44, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72
Offset: 1

Views

Author

Amarnath Murthy, Nov 01 2002

Keywords

Comments

Next available unused natural number is added to n-th row unless it would cause product for that row to exceed n prime divisors.

Examples

			2;
1,6;
3,4,5;
7,8,9,10;
11,12,13,14,16;
15,17,18,19,20,21;
...

Crossrefs

Cf. A077173, A077174, A077175, A077176, A100918.

Extensions

Extended by Ray Chandler, Nov 29 2004

A077176 Largest squarefree number that divides A077175(n).

Original entry on oeis.org

2, 6, 30, 210, 6006, 67830, 690690, 35303730, 3383531970, 29248649430, 1846079805570, 220495674290430, 15231748284963210, 328001307608664690, 58030069605260142390, 4938238739984380540710, 182365421703667931839110
Offset: 1

Views

Author

Amarnath Murthy, Nov 01 2002

Keywords

Crossrefs

Cf. A077172, A077173, A077174, A077175, A100918.

Extensions

Extended by Ray Chandler, Nov 29 2004

A077173 Initial terms of rows of triangle in A077172.

Original entry on oeis.org

2, 1, 3, 7, 11, 15, 22, 29, 37, 44, 56, 67, 78, 92, 106, 119, 136, 154, 171, 188, 210, 230, 252, 275, 299, 323, 349, 375, 402, 430, 460, 491, 522, 555, 588, 623, 658, 694, 731, 769, 809, 849, 890, 932, 975, 1019, 1064, 1110, 1157, 1205, 1255
Offset: 1

Views

Author

Amarnath Murthy, Nov 01 2002

Keywords

Crossrefs

Cf. A077172, A077174, A077175, A077176, A100918.

Extensions

Extended by Ray Chandler, Nov 29 2004

A077175 Product of terms in n-th row of triangle in A077172.

Original entry on oeis.org

2, 6, 60, 5040, 384384, 36628200, 5967561600, 1220096908800, 350804594649600, 97292707463952000, 42873948150095462400, 21336925409736330240000, 11640487097965528951948800, 7998487694738166709923840000
Offset: 1

Views

Author

Amarnath Murthy, Nov 01 2002

Keywords

Crossrefs

Cf. A077172, A077173, A077174, A077176, A100918.

Extensions

Extended by Ray Chandler, Nov 29 2004

A100918 A077175(n) / A077176(n).

Original entry on oeis.org

1, 1, 2, 24, 64, 540, 8640, 34560, 103680, 3326400, 23224320, 96768000, 764225280, 24385536000, 108391219200, 1097349120000, 29847896064000, 1631977611264000, 12384682168320000, 8034351316992000, 36502221127680000
Offset: 1

Views

Author

Ray Chandler, Nov 29 2004

Keywords

Crossrefs

Cf. A077172, A077173, A077174, A077175, A077176.
Showing 1-5 of 5 results.

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

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