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.

A307294 If n is even, a(n) = A000201(n/2+1), otherwise a(n) = A000201((n-1)/2+1) + 1.

Original entry on oeis.org

1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 9, 10, 11, 12, 12, 13, 14, 15, 16, 17, 17, 18, 19, 20, 21, 22, 22, 23, 24, 25, 25, 26, 27, 28, 29, 30, 30, 31, 32, 33, 33, 34, 35, 36, 37, 38, 38, 39, 40, 41, 42, 43, 43, 44, 45, 46, 46, 47, 48, 49, 50, 51, 51, 52, 53, 54, 55
Offset: 0

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Author

N. J. A. Sloane, Apr 12 2019

Keywords

Comments

It follows from the definition that a(2i+1) = a(2i)+1 for all i.

References

  • Eric Friedman, Scott M. Garrabrant, Ilona K. Phipps-Morgan, A. S. Landsberg and Urban Larsson, Geometric analysis of a generalized Wythoff game, in Games of no Chance 5, MSRI publ. Cambridge University Press, date? [See Omega, a few lines below Table 2.]

Crossrefs

Programs

  • Python
    from math import isqrt
    def A307294(n): return ((m:=(n>>1)+1)+isqrt(5*m**2)>>1)+(n&1) # Chai Wah Wu, Aug 10 2022