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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A132144 Numbers that can't be expressed as the sum of a prime number and a Fibonacci number (0 is considered to be a Fibonacci number).

Original entry on oeis.org

1, 35, 119, 125, 177, 208, 209, 221, 255, 287, 299, 329, 363, 416, 485, 515, 519, 535, 539, 551, 561, 567, 637, 697, 705, 718, 755, 768, 779, 784, 793, 815, 869, 875, 899, 925, 926, 933, 935, 951, 995, 1037, 1045, 1075, 1079, 1107, 1139, 1145, 1147, 1149
Offset: 1

Views

Author

Tanya Khovanova, Aug 12 2007

Keywords

Comments

This sequence is a subsequence of A132146 and the complement of A132145.

Examples

			The smallest prime number is 2, the smallest Fibonacci number is 0; hence 1 can't be presented as a sum of a prime number and a Fibonacci number.
		

References

  • J. Earls, "Fibonacci Prime Decompositions," Mathematical Bliss, Pleroma Publications, 2009, pages 76-79. ASIN: B002ACVZ6O [From Jason Earls, Nov 24 2009]

Programs

  • Mathematica
    nn = 17; f = Union[Fibonacci[Range[0, nn]]]; p = Prime[Range[PrimePi[f[[-1]]]]]; fp = Select[Union[Flatten[Outer[Plus, f, p]]], # < f[[-1]] &]; Complement[Range[f[[-1]] - 1], fp] (* T. D. Noe, Mar 06 2012 *)

A132147 Numbers that are the sum of a prime number and a positive Fibonacci number.

Original entry on oeis.org

3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76
Offset: 1

Views

Author

Tanya Khovanova, Aug 12 2007

Keywords

Comments

This sequence is a subsequence of A132145 and is the complement of A132146.
Lee shows that this sequence has positive lower density. - Charles R Greathouse IV, Nov 02 2010
The lower density of this sequence is at least 0.0254905 (Liu and Xue, 2021). - Amiram Eldar, Mar 04 2021

Examples

			11 = 3+8 is a term since it is the sum of a prime number (3) and a Fibonacci number (8).
		

Crossrefs

Programs

  • Mathematica
    Take[Union[Flatten[Table[Fibonacci[n] + Prime[k], {n, 70}, {k, 70}]]], 70]
  • PARI
    is(n)=my(k,f); while((f=fibonacci(k++))Charles R Greathouse IV, Sep 14 2015
Showing 1-2 of 2 results.