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A344830
a(n) is the smallest b > 1 such that prime(n), prime(n+1), prime(n+2), prime(n+3), prime(n+4) and prime(n+5) are all base-b Wieferich primes.
7
132857, 2006776, 296449, 17134811, 36763941, 34998229, 31239565, 968576295, 1027038511, 287811239, 15022368222, 33452659960, 19477999997, 132892045949, 47341045210, 32176849766, 106967760951, 303459122992, 20216391690, 1411108384416, 219517083156, 361244580521, 455588981749
OFFSET
1,1
LINKS
PROG
(PARI) a(n) = my(v=[prime(n)]); while(#v < 6, 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 6 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), A344829 (k=4), A344831 (k=6), A344832 (k=7).
Sequence in context: A242327 A339535 A319063 * A015407 A204536 A061732
KEYWORD
nonn
AUTHOR
Felix Fröhlich, May 29 2021
EXTENSIONS
Terms a(10) onward from Max Alekseyev, Oct 10 2023
STATUS
approved