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.

A283557 The number of positive integer sequences of length n with no duplicate substrings of length greater than 1 and a minimal product (= A282164(n)).

Original entry on oeis.org

1, 1, 3, 2, 2, 6, 6, 24, 24, 120, 120, 1200, 1440, 4320, 4320, 8640, 30240, 60480, 483840, 967680, 1935360, 3870720, 17418240, 34836480, 348364800, 696729600, 1741824000, 3483648000, 19160064000, 38320128000, 689762304000, 1379524608000, 9656672256000, 16554295296000, 66217181184000
Offset: 1

Views

Author

Peter Kagey, Mar 10 2017

Keywords

Comments

Surprisingly, a(n) = A282164(n) for n in { 1, 2, 4, 6, 8, 10, 13, 14, 19, 25, 32, 34, 35, ... }. - Max Alekseyev, Feb 06 2025

Examples

			For n = 7, the a(7) = 6 sequences are
1,3,1,2,2,1,1;
1,2,2,1,3,1,1;
1,3,1,1,2,2,1;
1,1,3,1,2,2,1;
1,2,2,1,1,3,1; and
1,1,2,2,1,3,1.
		

Crossrefs

A283558 is the sum analog.

Extensions

Terms a(11) onward from Max Alekseyev, Feb 06 2025

A284431 The number of positive integer sequences of length n with no duplicate substrings of length greater than 1, every number different from its neighbors, and a minimal sum (= A282166(n)).

Original entry on oeis.org

1, 2, 1, 6, 2, 42, 12, 116, 18, 84, 168, 336, 384, 6864, 7872, 67392, 52800, 357120, 115200, 748800, 3093120, 11681280, 26853120, 43130880, 74649600, 2238382080, 3588157440, 51775856640, 63188398080, 653811056640, 480220876800, 4284050964480, 1316818944000, 11061279129600, 76921038028800
Offset: 1

Views

Author

Peter Kagey, Mar 27 2017

Keywords

Examples

			For n = 5, the a(5) = 2 sequences are [1,3,1,2,1] and [1,2,1,3,1], each with a sum of A282166(5) = 8.
		

Crossrefs

Extensions

Terms a(9) onward from Max Alekseyev, Feb 06 2025

A284432 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1 and a minimal sum (= A282168(n)).

Original entry on oeis.org

1, 1, 2, 2, 4, 4, 4, 48, 48, 144, 144, 144, 2160, 8496, 21312, 110592, 203904, 407808, 815616, 1631232, 15667200, 31334400, 445114368, 890228736, 7291772928, 14583545856, 36458864640, 72917729280, 145835458560, 1694545920000, 16054441574400, 101226251059200, 421941436416000, 2144473989120000, 13603849760931840
Offset: 1

Views

Author

Peter Kagey, Mar 27 2017

Keywords

Examples

			For n = 7 the a(7) = 4 solutions are:
[1,3,3,2,2,1,1],
[1,2,2,3,3,1,1],
[1,1,3,3,2,2,1], and
[1,1,2,2,3,3,1].
		

Crossrefs

Extensions

Terms a(11) onward from Max Alekseyev, Feb 06 2025

A284433 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1, every number different from its neighbors, and a minimal sum (= A282167(n)).

Original entry on oeis.org

1, 2, 6, 2, 18, 12, 24, 24, 1320, 240, 528, 720, 5664, 105888, 16992, 150048, 244800, 4266432, 4375296, 39598848, 50637312, 123310080, 202549248, 15925690368, 3765657600, 23454351360, 101739110400, 437749678080, 1572538613760, 11891771080704, 7862693068800, 185042766200832
Offset: 1

Views

Author

Peter Kagey, Mar 27 2017

Keywords

Examples

			For n = 4 the a(4) = 2 solutions are [1,3,2,1] and [1,2,3,1].
		

Crossrefs

Extensions

Terms a(10) onward from Max Alekseyev, Feb 06 2025
Showing 1-4 of 4 results.