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A397375
Decimal expansion of Sum_{k>=1} (zeta(2) - H(k,2))*H(k)/(2*k+1), where H(k) = A001008(k)/A002805(k) is the k-th harmonic number, and H(k,2) = A007406(k)/A007407(k) is the k-th generalized harmonic number of order 2.
3
7, 7, 6, 9, 1, 3, 6, 1, 6, 1, 5, 6, 5, 8, 7, 7, 4, 9, 4, 4, 0, 0, 2, 9, 7, 4, 9, 9, 3, 8, 8, 5, 9, 1, 8, 8, 8, 1, 7, 8, 1, 0, 5, 0, 2, 3, 1, 1, 3, 1, 3, 5, 8, 0, 4, 8, 5, 9, 7, 8, 5, 9, 1, 4, 3, 0, 6, 0, 2, 5, 1, 0, 5, 1, 3, 7, 5, 7, 2, 4, 9, 7, 6, 5, 8, 5, 8, 3, 1, 0, 9, 3, 6, 2, 7, 5, 1, 4, 8, 8, 8, 1, 3, 2, 5
OFFSET
0,1
LINKS
Cornel Ioan Vălean, More (Almost) Impossible Integrals, Sums, and Series, Springer Cham, 2023. See section 4.29, p. 431, eq. (4.120), section 5.29, p. 463, section 6.29, pp. 646-651.
FORMULA
Equals log(2)^4/6 - log(2)^2*zeta(2) - zeta(4)/2 + 4*Li_4(1/2).
EXAMPLE
0.776913616156587749440029749938859188817810502311313...
MATHEMATICA
RealDigits[Log[2]^4/6 - Log[2]^2*Zeta[2] - Zeta[4]/2 + 4*PolyLog[4, 1/2], 10, 120][[1]]
PROG
(PARI) log(2)^4/6 - log(2)^2*zeta(2) - zeta(4)/2 + 4*polylog(4, 1/2)
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Jun 23 2026
STATUS
approved