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.

A040018 (Number of permutations of {1,2,...,n} for which sums of adjacent numbers are all distinct)/2n.

Original entry on oeis.org

1, 1, 3, 8, 46, 176, 955, 5446, 36122, 259084, 2043944, 17371318, 159616680, 1566391958
Offset: 3

Views

Author

Erich Friedman

Keywords

Comments

Essentially different ways 1,2,3,...,n can be placed around a circle so that sums of adjacent numbers are distinct.

Links

Crossrefs

Cf. A091217, A006967.

Extensions

a(10) from Vladeta Jovovic, Aug 25 2007
a(11)-a(13) from Steve Butler, Feb 08 2012
a(14)-a(16) from Sean A. Irvine, Mar 05 2021

A131529 Number of permutations of {1,2,...n} for which differences of adjacent numbers are all distinct.

Original entry on oeis.org

1, 2, 4, 12, 44, 176, 788, 3936, 23264, 152112, 1104876, 8725320, 74715908, 687915040, 6782261964, 71294227456, 796138700016, 9409401651840, 117378774461812
Offset: 1

Views

Author

Vladeta Jovovic, Aug 26 2007

Keywords

Links

Crossrefs

Cf. A040018, A091217, A006967.

Extensions

2 more terms from R. J. Mathar, Oct 25 2007
7 more terms from R. H. Hardin, Nov 26 2009

A147634 Number of permutations of 1..n with each sum of three adjacent terms unique.

Original entry on oeis.org

1, 2, 6, 16, 54, 232, 936, 4136, 19112, 98666, 559598, 3448160, 22951024, 164020894, 1255124388, 10182613618, 87879918338
Offset: 1

Views

Author

R. H. Hardin, Nov 09 2008

Keywords

Crossrefs

Cf. A091217.

Extensions

More terms from R. H. Hardin, Nov 11 2008
Showing 1-3 of 3 results.

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