A344829 a(n) is the smallest b > 1 such that prime(n), prime(n+1), prime(n+2), prime(n+3) and prime(n+4) are all base-b Wieferich primes.

19601, 54568, 13543, 296449, 3414284, 14380864, 3727271, 7916603, 65097619, 13793462, 152541840, 30495845, 91779237, 183068599, 558175167, 40698745, 825287029, 2151529020, 6271678163, 1266687934, 3149182509, 989067909, 10785363668, 18739432977, 4877709531, 24531035970, 11683733786, 52383593584

Offset

1,1

Links

Max Alekseyev, Table of n, a(n) for n = 1..100

Prog

(PARI) a(n) = my(v=[prime(n)]); while(#v < 5, v=concat(v, nextprime(v[#v]+1))); for(b=2, oo, for(k=1, #v, if(Mod(b, v[k]^2)^(v[k]-1)!=1, break, if(k==#v, return(b)))))

Crossrefs

Cf. A039678, A259075. Column 5 of A286816.

Cf. smallest b > 1 such that prime(n+i) is a base-b Wieferich prime for each i = 0..k: A039678 (k=0), A259075 (k=1), A344827 (k=2), A344828 (k=3), A344830 (k=5), A344831 (k=6), A344832 (k=7).

Sequence in context: A184493 A339534 A319062 * A221333 A069369 A156721

Adjacent sequences: A344826 A344827 A344828 * A344830 A344831 A344832

Keyword

nonn

Author

Felix Fröhlich, May 29 2021

Extensions

Terms a(22) onward from Max Alekseyev, Oct 10 2023

Status

approved