OFFSET
0,2
COMMENTS
See A262031 for this reordered alternating harmonic series with partial sums s(n).
FORMULA
a(n) = denominator(s(n)) with s(n) = Sum_{k=0..n} c(k), where c(k) = 3/(4*k+3), 3/(4*k+5), -3/(2*(k+1)) if k == 0, 1, 2 (mod 3), respectively.
EXAMPLE
See A262031 for s(n), n=0..11, and s(10^n) for n=0..6.
PROG
(PARI) lista(nn) = {my(s = 0); for (k=0, nn, if (k%3==2, t = -3/(2*(k+1)), if (k%3==1, t = 3/(4*k+5), t = 3/(4*k+3))); s += t; print1(denominator(s), ", "); ); } \\ Michel Marcus, Sep 13 2015
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
Wolfdieter Lang, Sep 08 2015
STATUS
approved