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.

A054016 a(n) = smallest nonnegative integer not the Nim sum of at most 4 earlier terms.

Original entry on oeis.org

1, 2, 4, 8, 16, 31, 32, 64, 103, 128, 171, 213, 256, 301, 342, 439, 475, 494, 512, 558, 595, 911, 1024, 1075, 1114, 1189, 1287, 1606, 1727, 1996, 2048, 2102, 2140, 2225, 2339, 2667, 2691, 3240, 3733, 4096, 4153, 4171, 4371, 4745, 4912, 5237, 5601, 5746
Offset: 1

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Author

N. J. A. Sloane, Apr 29 2000

Keywords

Comments

Grundy function for turn-at-most-5-coins game.

References

  • E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982, see Table 3, Chapter 14, p. 433.

Crossrefs

Cf. A000069, A033623, A054043, etc.

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Oct 31 2000

A033623 Grundy function for turn-at-most-4-coins game.

Original entry on oeis.org

1, 2, 4, 8, 15, 16, 32, 51, 64, 85, 106, 128, 150, 171, 219, 237, 247, 256, 279, 297, 455, 512, 537, 557, 594, 643, 803, 863, 998, 1024, 1051, 1070, 1112, 1169, 1333, 1345, 1620, 1866, 2048, 2076, 2085, 2185, 2372
Offset: 1

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Author

Keywords

References

  • E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Table 3, page 433.

Crossrefs

Cf. A000069, A054016, A054043, etc.

Programs

  • Mathematica
    Clear[a]; a[1] = 1; a[n_] := a[n] = (xor = BitXor @@@ Subsets[Array[a, n-1], 3] // Union ; r = Range[0, m = Last[xor]]; cp = Complement[r, xor]; If[cp == {}, m+1, First[cp]]); Table[a[n], {n, 1, 43}] (* Jean-François Alcover, Jan 09 2013 *)

Formula

a(n)=smallest natural not the exclusive-or of at most three a(k) for k

Extensions

More terms from N. J. A. Sloane Apr 29 2000

A054041 Sum of a(n) terms of 1/k^(1/3) first exceeds n.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 12, 15, 17, 20, 23, 25, 28, 32, 35, 38, 41, 45, 49, 52, 56, 60, 64, 68, 72, 76, 81, 85, 89, 94, 98, 103, 108, 113, 117, 122, 127, 132, 138, 143, 148, 153, 159, 164, 170, 175, 181, 187, 192, 198, 204, 210, 216, 222, 228, 234, 240, 247, 253, 259
Offset: 0

Author

Asher Auel, Apr 13 2000

Keywords

Crossrefs

Programs

  • Mathematica
    s = 0; k = 1; Do[ While[ s <= n, s = s + N[ 1/k^(1/3), 24 ]; k++ ]; Print[ k - 1 ], {n, 1, 75} ]

Extensions

Corrected and extended by Robert G. Wilson v, Aug 01 2000
Edited by N. J. A. Sloane, Jan 17 2009 at the suggestion of R. J. Mathar
Showing 1-3 of 3 results.