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A336372 Primes p(n) such that gcd(n, prime(n)+prime(n-1)) = 1. 4
3, 5, 11, 17, 31, 59, 67, 83, 97, 109, 127, 137, 149, 157, 179, 191, 211, 227, 241, 257, 277, 283, 331, 353, 367, 379, 389, 401, 431, 439, 449, 461, 467, 509, 547, 563, 587, 599, 607, 617, 653, 691, 709, 739, 751, 773, 797, 823, 829, 859, 877, 907, 919, 947 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

This sequence and A336373 partition the set of odd primes.

LINKS

Table of n, a(n) for n=2..55.

EXAMPLE

In the following table, p(n) = A000040(n) = prime(n).

  n    p(n)   p(n)+p(n-1)   gcd

  2     3         5          1

  3     5         8          1

  4     7        12          4

  5    11        18          1

  6    13        24          6

MATHEMATICA

p[n_] := Prime[n];

u = Select[Range[2, 200], GCD[#, p[#] + p[# - 1]] == 1 &]  (* A336370 *)

v = Select[Range[2, 200], GCD[#, p[#] + p[# - 1]] > 1 &]   (* A336371 *)

Prime[u]  (* A336372 *)

Prime[v]  (* A336373 *)

CROSSREFS

Cf. A000040, A336366, A336370, A336371, A336373.

Sequence in context: A006450 A085918 A267094 * A146622 A124179 A124173

Adjacent sequences:  A336369 A336370 A336371 * A336373 A336374 A336375

KEYWORD

nonn

AUTHOR

Clark Kimberling, Oct 05 2020

STATUS

approved

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Last modified April 13 00:24 EDT 2021. Contains 342934 sequences. (Running on oeis4.)