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.

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A006133 Related to representations as sums of Fibonacci numbers.

Original entry on oeis.org

3, 21, 32, 79, 144, 155, 173, 202, 220, 231, 401, 524, 542, 553, 600, 922, 987, 998, 1016, 1045, 1063, 1074, 1121, 1139, 1150, 1168, 1186, 1197, 1215, 1244, 1367, 1385, 1396, 1443, 1508, 1519, 1537, 1566, 1584, 1595, 1765, 2608, 2731, 2749, 2760, 2807, 3129
Offset: 1

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Author

Keywords

Comments

Common value of A003231(x) and A003234(x) for x in A006132 (see Table 1 p. 357 in Carlitz link). - Michel Marcus, Feb 02 2014

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • PARI
    A001950(n) = floor(n*(sqrt(5)+3)/2); \\ b
    A003231(n) = floor(n*(sqrt(5)+5)/2); \\ c
    iss(n) = A003231(A001950(n)) == A001950(A003231(n)) - 1;
    lista(nn) = {v003231 = vector(nn, i, floor(i*(sqrt(5)+5)/2)); v003234 = select(n->iss(n), vector(5*nn, i, i)); for (n=1, nn, if (v003231[n] == v003234[n], print1(v003231[n], ", ")););}  \\ Michel Marcus, Feb 02 2014

Formula

a(n) = A003231(A006132(n)) = A003234(A006132(n)). - Michel Marcus, Feb 02 2014

Extensions

More terms from Michel Marcus, Feb 02 2014

A306683 Integers k for which the base-phi representation of k does not include 1 or phi.

Original entry on oeis.org

3, 5, 7, 10, 12, 14, 16, 18, 21, 23, 25, 28, 30, 32, 34, 36, 39, 41, 43, 45, 47, 50, 52, 54, 57, 59, 61, 63, 65, 68, 70, 72, 75, 77, 79, 81, 83, 86, 88, 90, 92, 94, 97, 99, 101, 104, 106, 108, 110, 112, 115, 117, 119, 121, 123, 126, 128, 130, 133, 135, 137, 139, 141, 144
Offset: 1

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Author

Michel Dekking, May 06 2019

Keywords

Comments

Let b = A214970 be the sequence of the integers k for which the base phi representation includes 1, and let c be the sequence of integers k for which the base phi representation includes phi.
Note that a, b and c form a complementary triple (since consecutive digits 11 do not occur in a base phi representation).
Conjecture (Moses 2012/Baruchel 2018): b is the generalized Beatty sequence b(n) = floor(n*phi) + 2*n + 1.
Conjecture (Kimberling 2012): c = A054770 = A000201(n) + 2*n - 1 = floor(n*phi) + 2*n - 1.
One can prove that the Moses/Baruchel conjecture and the Kimberling conjecture are equivalent.
Conjecture: (a(n)) is a union of two generalized Beatty sequences v and w, given by v(n) = floor(n*phi) + 2*n = A003231(n), and w(n) = 3*floor(n*phi) + n + 1 = A190509(n) + 1.
This conjecture is compatible with the Moses/Baruchel/Kimberling conjecture.
These three conjectures are proved in my paper 'Base phi representations and golden mean beta-expansions'. - Michel Dekking, Jun 26 2019

Examples

			3 = phi^2 + phi^{-2}, 5 = phi^3 + phi^{-1} + phi^{-4}.
		

Crossrefs

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