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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.

A086031 Number of nonisomorphic ways a loop can cross two parallel roads 2n times.

Original entry on oeis.org

1, 1, 3, 7, 37, 207, 1470, 11169, 91166, 776841, 6865598, 62443973
Offset: 0

Views

Author

N. J. A. Sloane and Jon Wild, Aug 25 2003

Keywords

Comments

There is no obligation to cross the lower road (cf. A077054).

Crossrefs

Cf. A077054. Isomorphism classes from A085973.

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

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