A224755 a(2)=4; thereafter a(n) = smallest number m such that a(n-1)+m = (a(n-1) followed by the leading digit of m).

4, 39, 354, 3189, 28703, 258329, 2324963, 20924669, 188322022, 1694898199, 15254083792, 137286754129, 1235580787162, 11120227084459, 100082043760132, 900738393841197, 8106645544570781, 72959809901137036, 656638289110233330, 5909744601992099975, 53187701417928899780, 478689312761360098024, 4308203814852240882220, 38773834333670167939983

Offset

1,1

Comments

The sequence is infinite: a(n) always exists.

For computer programs and examples see A224752.

References

Eric Angelini, Postings to the Sequence Fans Mailing List, Apr 13 2013

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Eric Angelini, Magic Sums

E. Angelini, Magic Sums [Cached copy, with permission]

Mathematica

snm[n_]:=Module[{b=Range[9n+1, 9n+9]}, First[Select[b, n+#==10n+First[ IntegerDigits[ #]]&, 1]]]; NestList[snm, 4, 25] (* Harvey P. Dale, May 05 2013 *)

Crossrefs

Cf. A224752-A224761.

Sequence in context: A059945 A198853 A093851 * A241075 A123618 A199757

Adjacent sequences: A224752 A224753 A224754 * A224756 A224757 A224758

Keyword

nonn,base

Author

N. J. A. Sloane, Apr 21 2013

Status

approved