A343798 a(n) is the least k such that A343796(k) = n, or 0 if there is no such k.

1, 2, 4, 7, 25, 12, 16, 37, 24, 32, 33, 40, 67, 63, 48, 58, 78, 60, 81, 50, 102, 91, 114, 109, 110, 116, 117, 124, 130, 137, 120, 128, 152, 168, 190, 183, 184, 186, 215, 199, 206, 202, 259, 235, 208, 264, 261, 256, 269, 274, 281, 318, 272, 301, 316, 330, 329, 342, 327, 352, 326, 376, 346, 312

Offset

0,2

Comments

a(n) is the least k such that there are exactly n distinct primes of the form A007504(k) mod p for the first k primes p.

Links

Robert Israel, Table of n, a(n) for n = 0..1000

Example

a(4) = 25 because A007504(25) = 1060 and there are 4 primes of the form 1060 mod p for the first 25 primes p: 2 = 1060 mod 23, 3 = 1060 mod 7, 7 = 1060 mod 13 and 23 = 1060 mod 61, and 25 is the first k that produces exactly 4 primes in this way.

Maple

N:= 100: # for a(0)..a(N)
V:= Array(0..N): count:= 0:
P:= {}: p:= 1: t:= 0:
for n from 1 while count < 100 do
p:= nextprime(p); P:= P union {p}; t:= t+p;
v:= nops(select(isprime, map(s -> t mod s, P)));
if v <= N and V[v] = 0 then
  V[v]:= n; count:= count+1;
fi
od:
convert(V, list);

Crossrefs

Cf. A007504, A343796.

Sequence in context: A359095 A036440 A103001 * A222987 A222907 A179386

Adjacent sequences: A343795 A343796 A343797 * A343799 A343800 A343801

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Apr 29 2021

Status

approved