Cf.
A006752 (decimal expansion of Catalan's constant).
Cf.
A224615 (number of times the digit 0 appears).
Cf.
A224616 (number of times the digit 1 appears).
Cf.
A224696 (number of times the digit 2 appears).
Cf.
A224706 (number of times the digit 3 appears).
Cf.
A224774 (number of times the digit 5 appears).
Cf.
A224775 (number of times the digit 6 appears).
Cf.
A224816 (number of times the digit 7 appears).
Cf.
A224817 (number of times the digit 8 appears).
Cf.
A224818 (number of times the digit 9 appears).