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A163125 Sum of digits of the n-th Colombian number, A003052(n). 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 22 13:12 EDT 2022. Contains 353950 sequences. (Running on oeis4.)