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A100194 Incrementally largest denominators of the Bernoulli numbers. 5
1, 2, 6, 30, 42, 66, 2730, 14322, 1919190, 56786730, 140100870, 209191710, 2328255930, 2381714790, 7225713885390, 9538864545210, 21626561658972270, 446617991732222310, 115471236091149548610, 5145485882746933233510, 14493038256293268734790 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Daniel Suteu, Table of n, a(n) for n = 1..85

Eric Weisstein's World of Mathematics, Bernoulli Number

Wikipedia, Von Staudt-Clausen theorem

MATHEMATICA

Reap[For[n = record = 0, n < 1000, n = n + 2, If[(d = Denominator[BernoulliB[n]]) > record, Sow[d]; record = d]]][[2, 1]] (* Jean-Fran├žois Alcover, Nov 09 2012 *)

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(d, ", "))); }

lista(1000); \\ Daniel Suteu, Dec 22 2018

CROSSREFS

Cf. A100195, A000367/A002445.

Sequence in context: A265501 A090801 A166062 * A229882 A325986 A298759

Adjacent sequences:  A100191 A100192 A100193 * A100195 A100196 A100197

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, Nov 08 2004

EXTENSIONS

a(21) from Seiichi Manyama, Jan 21 2017

STATUS

approved

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Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)