A163125 Sum of digits of the n-th Self-number (or Colombian number), A003052(n).

1, 3, 5, 7, 9, 2, 4, 6, 8, 10, 12, 14, 16, 9, 2, 4, 6, 8, 10, 12, 14, 16, 18, 11, 4, 6, 8, 10, 12, 14, 16, 18, 20, 4, 6, 8, 10, 12, 14, 16, 18, 20, 4, 6, 8, 10, 12, 14, 16, 18, 20, 13, 6, 8, 10, 12, 14, 16, 18, 20, 13, 15, 8, 10, 12, 14, 16, 18, 20, 13, 15, 17, 10, 12, 14, 16, 18, 20, 13

Offset: 1

Author

Juri-Stepan Gerasimov, Jul 21 2009

Keywords

• nonn
• base

Examples

			a(6) = 2 + 0 = 2;
a(7) = 3 + 1 = 4.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A003052, A007953.

Programs

Maple

A007953 := proc(n) add( d,d= convert(n,base,10) ); end:
isA003052 := proc(n) local k ; for k from 0 to n do if k+A007953(k) = n then RETURN(false): fi; od: RETURN(true) ; end:
A003052 := proc(n) option remember; if n = 1 then 1; else for a from procname(n-1)+1 do if isA003052(a) then RETURN(a) ; fi; od; fi; end:
A163125 := proc(n) A007953( A003052(n)) ; end: seq(A163125(n),n=1..100) ; # R. J. Mathar, Jul 27 2009

Mathematica

sumdig[n_] := Plus @@ IntegerDigits[n]; m = 500; sumdig /@ Complement[Range[m], Table[n + sumdig[n], {n, 1, m}]] (* Amiram Eldar, Nov 28 2020 *)

Formula

a(n) = A007953(A003052(n)).

Extensions

Values after a(51) corrected by R. J. Mathar, Jul 27 2009