A077492 a(n) = smallest k such that 5k has a digit sum = n.

2, 4, 6, 8, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 39, 59, 79, 99, 119, 139, 159, 179, 199, 399, 599, 799, 999, 1199, 1399, 1599, 1799, 1999, 3999, 5999, 7999, 9999, 11999, 13999, 15999, 17999, 19999, 39999, 59999, 79999, 99999, 119999, 139999, 159999, 179999

Offset: 1

Author

Amarnath Murthy, Nov 07 2002

Keywords

• base
• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,10,-10).

Crossrefs

Cf. A069532, A069534.

Programs

Mathematica

LinearRecurrence[{1, 0, 0, 0, 0, 0, 0, 0, 10, -10},{2, 4, 6, 8, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19}, 40] (* Georg Fischer, Oct 26 2020 *)

Formula

a(n) = A069534(n)/5.

a(n) = a(n-1) + 10*a(n-9) - 10*a(n-10) for n > 14. - Georg Fischer, Oct 26 2020

Extensions

More terms from Ray Chandler, Jul 28 2003