A392310 Decimal expansion of the continued fraction [sigma*(1), sigma*(2), sigma*(3), sigma*(4), ...], where sigma*(k) is the sum of antidivisors of k.

4, 3, 2, 2, 6, 2, 0, 8, 1, 5, 1, 0, 8, 5, 4, 9, 5, 1, 9, 8, 5, 0, 7, 9, 5, 5, 9, 7, 3, 0, 0, 0, 5, 7, 8, 7, 2, 7, 2, 0, 2, 4, 8, 0, 0, 2, 8, 5, 1, 3, 3, 8, 8, 8, 3, 2, 5, 8, 0, 0, 9, 0, 2, 9, 0, 7, 8, 1, 9, 8, 8, 1, 4, 0, 3, 0, 2, 2, 3, 5, 7, 7, 6, 9, 5, 0, 6

Offset

0,1

Comments

0.432262081510854951985079559730... = [0, 0, 2, 3, 5, 4, 10, 8, 8, 14, 12, 13, 19, 16, 18, ...]

Links

Table of n, a(n) for n=0..86.

Maple

with(numtheory): A:=proc(w) local j, k; k:=0; j:=w; while j mod 2<>1 do k:=k+1; j:=j/2; od;
sigma(2*w+1)+sigma(2*w-1)+sigma(w/2^k)*2^(k+1)-6*w-2; end:
P:=proc(q) local a, n; a:=A(q+1); for n from q by -1 to 3 do a:=1/a+A(n); od;
print(evalf(1/a, 100)); end: P(10^3);

Crossrefs

Cf. A066417, A223854.

Sequence in context: A138851 A181061 A329934 * A269611 A090342 A010307

Adjacent sequences: A392307 A392308 A392309 * A392311 A392312 A392313

Keyword

nonn,cons

Author

Paolo P. Lava, Apr 01 2026

Status

approved