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URL: https://oeis.org/A100195

⇱ A100195 - OEIS

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A100195
Numbers n such that the denominator of BernoulliB(n) is a record.
5
0, 1, 2, 4, 6, 10, 12, 30, 36, 60, 72, 108, 120, 144, 180, 240, 360, 420, 540, 840, 1008, 1080, 1200, 1260, 1620, 1680, 2016, 2160, 2520, 3360, 3780, 5040, 6480, 7560, 8400, 10080, 12600, 15120, 25200, 30240, 42840, 45360, 55440, 60480, 75600, 85680, 100800
OFFSET
1,3
LINKS
Eric Weisstein's World of Mathematics, Bernoulli Number
MATHEMATICA
DeleteDuplicates[Table[{n, Denominator[BernoulliB[n]]}, {n, 0, 101000}], GreaterEqual[#1[[2]], #2[[2]]]&][[;; , 1]] (* Harvey P. Dale, Jul 22 2025 *)
PROG
(PARI) b(n) = if((n==0) || (n>1 && n%2==1), 1, my(d=divisors(n)); prod(k=1, #d, if(isprime(d[k]+1), d[k]+1, 1))); \\ more efficient than denominator(bernfrac(n))
lista(n) = { my(m=0); for(k=0, n, my(d=b(k)); if(d>m, m=d; print1(k, ", "))); }
lista(100000); \\ Daniel Suteu, Dec 23 2018
CROSSREFS
Cf. A100194 (the corresponding Bernoulli denominators), A000367/A002445.
Sequence in context: A095923 A094960 A357110 * A032396 A271884 A305836
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Nov 08 2004
EXTENSIONS
Corrected and extended by Daniel Suteu, Dec 23 2018
STATUS
approved