OFFSET
1,1
COMMENTS
a(n) is an odd integer for all n, a(n)=1 infinitely often, and a(n)=p infinitely often for every odd prime p. See Cor. 2 and Cor. 3 in "The denominators of power sums of arithmetic progressions". See also "Power-sum denominators".
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Bernd C. Kellner, On a product of certain primes, J. Number Theory, 179 (2017), 126-141; arXiv:1705.04303 [math.NT], 2017.
Bernd C. Kellner and Jonathan Sondow, Power-Sum Denominators, Amer. Math. Monthly, 124 (2017), 695-709; arXiv:1705.03857 [math.NT], 2017.
Bernd C. Kellner and Jonathan Sondow, The denominators of power sums of arithmetic progressions, Integers 18 (2018), #A95, 17 pp.; arXiv:1705.05331 [math.NT], 2017.
MATHEMATICA
b[n_] := Denominator[ Together[ BernoulliB[n, x]]]; Table[ b[2 n]/b[2 n + 1], {n, 1, 67}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Bernd C. Kellner and Jonathan Sondow, May 12 2017
STATUS
approved