A092904 - OEIS

A092904

Number of decimal digits in the denominator of the Bernoulli number B(2n).

1, 1, 2, 2, 2, 2, 4, 1, 3, 3, 3, 3, 4, 1, 3, 5, 3, 1, 7, 1, 5, 4, 3, 3, 5, 2, 4, 3, 3, 3, 8, 1, 3, 5, 2, 4, 9, 1, 2, 4, 6, 3, 7, 1, 5, 6, 4, 1, 7, 1, 5, 4, 4, 3, 9, 4, 7, 2, 4, 1, 10, 1, 2, 7, 3, 4, 7, 1, 4, 6, 6, 1, 10, 1, 4, 7, 2, 3, 10, 1, 6, 6, 4, 4, 7, 2, 4, 4, 7, 4, 13, 1, 4, 2, 2, 5, 9, 1, 6, 9, 7

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Jwalin Bhatt, Table of n, a(n) for n = 0..5000 (first 1000 terms from Seiichi Manyama).

FORMULA

a(n) = A055642(A002445(n)). - Jwalin Bhatt, Nov 05 2025

MATHEMATICA

Table[IntegerLength@ Denominator@ BernoulliB[2 n], {n, 0, 100}] (* Michael De Vlieger, Jan 20 2017 *)

PROG

(PARI) a(n)=logint(denominator(bernfrac(2*n)), 10)+1 \\ Jwalin Bhatt, Nov 06 2025

(Python)

from sympy import bernoulli

def A092904(n): return len(str(bernoulli(2*n).denominator)) # Jwalin Bhatt, Nov 05 2025

CROSSREFS

Cf. A000367, A002445, A068399 (numerator).

Sequence in context: A125914 A382489 A086668 * A231883 A370690 A062816

Adjacent sequences: A092901 A092902 A092903 * A092905 A092906 A092907

KEYWORD

nonn,base

AUTHOR

Eric W. Weisstein, Mar 12 2004

STATUS

approved