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

1,2

Links

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

Formula

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

Example

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

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 *)

Crossrefs

Cf. A003052, A007953.

Sequence in context: A032764 A131669 A004155 * A167047 A065271 A213542

Adjacent sequences: A163122 A163123 A163124 * A163126 A163127 A163128

Keyword

nonn,base

Author

Juri-Stepan Gerasimov, Jul 21 2009

Extensions

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

Status

approved