A073866 a(n) is the smallest composite number with the sum of digits = the n-th composite number.

4, 6, 8, 9, 28, 39, 68, 69, 88, 99, 299, 399, 589, 699, 799, 899, 999, 2899, 3999, 5999, 6999, 7999, 9899, 9999, 29999, 39999, 58999, 69999, 89999, 99999, 299899, 399999, 499999, 689999, 699999, 889999, 999999, 1999999, 3899999, 3999999, 5899999, 6999999, 8999999, 9999999

Offset

1,1

Links

Table of n, a(n) for n=1..44.

Example

a(5) = 28, because 10 is the 5th composite, and 28 is the first composite with sum of digits equal to 10. - Michel Marcus, May 19 2014

Prog

(PARI) lista(nn) = {vn = vector(nn, i, i); vc = select(x->iscomp(x), vn); vsd = vector(#vc, i, sumdigits(vc[i])); for (i=1, #vc, print1(vc[select(x->(x==vc[i]), vsd, 1)[1]], ", "); ); } \\ Michel Marcus, May 19 2014

Crossrefs

Cf. A002808, A073868, A075360.

Sequence in context: A287198 A099071 A156673 * A202260 A001744 A113624

Adjacent sequences: A073863 A073864 A073865 * A073867 A073868 A073869

Keyword

base,nonn

Author

Amarnath Murthy, Aug 15 2002

Extensions

More terms from Michel Marcus, May 19 2014

Status

approved