A361931 a(n) is the smallest number k such that A361929(k) = prime(n), or -1 if no such prime exists.

1, 2, 7, 10, 26, 177, 508, 13812, 73873, 4638434, 4638435, 1874400183, 114936835817

Offset

1,2

Comments

It is conjectured that all primes appear in A361929.

Links

Table of n, a(n) for n=1..13.

Mathematica

K = {2}; R = {1}; r = 2; z = 1; While[Length@R < 9, z++; p = 2; While[MemberQ[K[[Length@K - GCD[z - 1, Last@K] + 1 ;; Length@K]], p], p = NextPrime[p]]; AppendTo[K, p]; If[p > r, AppendTo[R, z]; r = p]; If[Length@K > NextPrime[r], K = K[[Length@K - NextPrime[r] ;; Length@K]]]]; Print[R]

Crossrefs

Cf. A361929.

Sequence in context: A362683 A032007 A091295 * A215407 A084184 A015963

Adjacent sequences: A361928 A361929 A361930 * A361932 A361933 A361934

Keyword

nonn,more

Author

Samuel Harkness, Mar 30 2023

Extensions

a(12)-a(13) from Kevin Ryde, Apr 01 2023

Status

approved