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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A270532 Integers k such that A003266(p) is not divisible by p*(p+1)/2 where p is the k-th prime.

Original entry on oeis.org

1, 2, 4, 9, 14, 19, 23, 27, 31, 38, 39, 48, 49, 61, 73, 76, 86, 90, 91, 93, 96, 99, 101, 107, 111, 117, 118, 124, 129, 138, 143, 144, 150, 153, 154, 155, 161, 166, 179, 188, 192, 195, 208, 213, 217, 219, 224, 229, 236, 243, 247, 250, 253, 258, 261, 262, 269, 272, 276, 277, 283, 285, 292, 300
Offset: 1

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Author

Altug Alkan, Mar 18 2016

Keywords

Comments

See A000057 to corresponding prime numbers. In other words, this sequence is an indirect way to generate primes dividing all Fibonacci sequences.

Crossrefs

Programs

  • PARI
    f(n) = prod(k=1, n, fibonacci(k)); \\ A003266
    isok(n) = (lift(Mod(f(prime(n)),(prime(n)*(prime(n)+1)/2))) != 0);
    
  • PARI
    isok(n) = my(p=prime(n), m=p*(p+1)/2); prod(k=1, p, Mod(fibonacci(k), m)); \\ Michel Marcus, May 14 2021
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