OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = denominator of (3/2)*(digamma(n+5/2) + 2*log(2) + euler_gamma).
a(n) = denominator of ( 3*Sum_{j=0..n+1} 1/(2*j+1) ).
a(n) = (1/3) * denominator of ( 2*H_{2*n+4} - H_{n+2} ), where H_{n} is the n-th Harmonic number. - G. C. Greubel, Jul 24 2023
MATHEMATICA
f[x_]:= 2*x+1; a[1]= f[1]; a[n_]:= LCM[f[n], a[n-1]]; Array[a, 21]/3 (* Robert G. Wilson v, Jan 04 2013 *)
PROG
(Magma) [Denominator((2*HarmonicNumber(2*n+4) - HarmonicNumber(n+2)))/3: n in [0..40]]; // G. C. Greubel, Jul 24 2023
(SageMath) [denominator(2*harmonic_number(2*n+4, 1) - harmonic_number(n+2, 1))/3 for n in range(41)] # G. C. Greubel, Jul 24 2023
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Aug 19 2005
EXTENSIONS
Name edited by G. C. Greubel, Jul 24 2023
STATUS
approved