Problem: mysterious numbers

Code: mysterious+numbers/tails+%28whio%29_1771402494

Nibbles version: 0.2 | 0.21 | 0.22 | 0.23 | 0.24 | 0.25 | 1.00

Format: Compact | Simple | +Type | Table | JSON | .nbl (DeBruijn) | .nbl (names)

or (or):[int] 
    / (foldr):[int] 
        _ (= ints):[int] 
        | (filter):[int] <--arg( B:int A:int ) 
            ;@ (= ints):[int] 
            - (subtract):int <--arg( C:int ) 
                $ (= C):int 
                ~ (auto = 1):auto 
        `% (split list (keep empties)):[[int]] <--arg( E:int D:[int] ) 
            @ (= D):[int] 
            : (append):[int] 
                + (add):int 
                    % (modulus):int 
                        $ (= E):int 
                        3 (integer):int 
                    3 (integer):int 
                2 (integer):int 
    1 (integer):int <--arg( F:int )