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A144980
Natural numbers k such that k+1 is divisible by the sum of the decimal digits of k.
4
1, 10, 11, 14, 19, 31, 34, 65, 71, 79, 100, 101, 103, 104, 109, 143, 160, 164, 167, 211, 215, 223, 263, 293, 299, 337, 362, 367, 379, 412, 419, 431, 454, 458, 461, 479, 503, 545, 560, 571, 601, 655, 659, 671, 689, 764, 769, 799, 805, 839, 892, 896, 917, 922
OFFSET
1,2
COMMENTS
The complement of this sequences is A178338.
The sequence is infinite since if m = 10^j then (m+1) / digitsum(m) = m. - Marius A. Burtea, Dec 21 2018
LINKS
EXAMPLE
1+1 = 2 is divisible by 1, hence 1 is in the sequence; 65+1 = 66 is divisible by 6+5 = 11, hence 65 is in the sequence.
MAPLE
A007953 := proc(n) local d; add(d, d=convert(n, base, 10)) ; end: isA144980 := proc(n) RETURN( (n+1) mod A007953(n) = 0 ) ; end: for n from 1 to 1800 do if isA144980(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Sep 30 2008
MATHEMATICA
Select[Range[2000], Mod[#+1, Total[IntegerDigits[#]]]==0&] (* Harvey P. Dale, Nov 13 2010 *)
PROG
(Magma) [n: n in [1..2000]|IsIntegral((n+1)/&+Intseq(n))]; // Marius A. Burtea, Dec 18 2018
CROSSREFS
Cf. A144967.
Cf. A005349. - R. J. Mathar, Sep 30 2008
Sequence in context: A335237 A214864 A062844 * A261713 A244283 A373615
KEYWORD
nonn,base,easy
AUTHOR
Giovanni Teofilatto, Sep 28 2008
EXTENSIONS
a(1) inserted, extended beyond a(7). Example added, cross-reference added. Keyword base added, keyword more deleted, offset changed from 1,1 to 1,2. - Klaus Brockhaus, Sep 30 2008
Extended by R. J. Mathar, Sep 30 2008
STATUS
approved