A344829 - OEIS

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

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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