A051885(n) = ((n%9)+1)*10^(n\9)-1
A228915(n) = \
	my (r=0, p=0, d); \
	while (1, \
		d = n%10; \
		if (d<9 && r>0, \
			return ((n+1)*10^p + A051885(r-1)) \
		); \
		n = n\10; \
		p = p+1; \
		r = r+d \
	)

s2n = [1, 2]
peek(s) = {
	while (#s2n < s,
		s2n = concat(s2n, A051885(#s2n+1));
	);
	if (s>0,
		return (s2n[s]),
		return (oo)
	);
}

{
	for (n=1, 1 000 000,
		if (n<=2,
			v = n,
			v = vecmin([peek(p-pp),
			            peek(pp-p),
			            peek(pp+p)]);
		);
		ds = sumdigits(v);
		s2n[ds] = A228915(s2n[ds]);

		print (n " " v);

		[pp,p]=[p,ds]
	);
}

quit