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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A004397 a(n) = prime(n) + Fibonacci(n).

Original entry on oeis.org

3, 4, 7, 10, 16, 21, 30, 40, 57, 84, 120, 181, 274, 420, 657, 1040, 1656, 2645, 4248, 6836, 11019, 17790, 28740, 46457, 75122, 121494, 196521, 317918, 514338, 832153, 1346396, 2178440, 3524715, 5703026, 9227614, 14930503, 24157974, 39088332, 63246153
Offset: 1

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Author

Hegermann, Frank (hegermann(AT)oi.dbv.commerzbank.dbp.de)

Keywords

References

  • GCHQ, The GCHQ Puzzle Book, Penguin, 2016. See page 79.

Crossrefs

Cf. A100700.

Programs

  • Magma
    [NthPrime(n)+Fibonacci(n): n in [1..50]]; // Vincenzo Librandi, Jul 29 2016
  • Maple
    with(combinat): f := n -> fibonacci(n) + ithprime(n);
  • Mathematica
    Table[Fibonacci[n] + Prime[n], {n, 35}]

A102867 Prime differences between k-th prime and k-th Fibonacci number.

Original entry on oeis.org

-2, -3, -5, 2, 11, 107, 563, 46279, 3524441, 4807526753, 47068900554068939361891195233676009091941689423
Offset: 1

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Author

Jonathan Vos Post, Mar 01 2005

Keywords

Comments

Note that for k>3, F(k) - Prime(k) cannot be prime if k is prime.
The next term -- a(11) -- has 110 digits. - Harvey P. Dale, Mar 19 2017

Examples

			F(2)-Prime(2) = 1 - 3 = -2.
F(3)-Prime(3) = 2 - 5 = -3.
F(6)-Prime(6) = 8 - 13 = -5.
F(8)-Prime(8) = 21 - 19 = 2.
F(9)-Prime(9) = 34 - 23 = 11.
F(12)-Prime(12) = 144 - 37 = 107.
F(15)-Prime(15) = 610 - 47 = 563.
F(24)-Prime(24) = 46368 - 89 = 46279.
F(33)-Prime(33) = 3524578 - 137 = 3524441.
		

Crossrefs

Programs

  • Mathematica
    With[{nn=600},Select[#[[1]]-#[[2]]&/@Thread[{Fibonacci[Range[nn]], Prime[ Range[ nn]]}],PrimeQ]] (* Harvey P. Dale, Mar 19 2017 *)

Formula

Fibonacci(k) - Prime(k) iff prime. Intersection of {A000045(i) - A000040(i)} and {A000040(j)}. Prime values of A100700.

Extensions

More terms from Harvey P. Dale, Mar 19 2017
Showing 1-2 of 2 results.