A101813 Odd Niven (or Harshad) numbers: odd numbers that are divisible by the sum of their digits.

1, 3, 5, 7, 9, 21, 27, 45, 63, 81, 111, 117, 133, 135, 153, 171, 195, 201, 207, 209, 225, 243, 247, 261, 285, 315, 333, 351, 375, 399, 405, 407, 423, 441, 465, 481, 511, 513, 531, 555, 603, 605, 621, 629, 645, 711, 715, 735, 777, 801, 803, 825, 915, 935, 999

Offset

1,2

References

David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, p. 171.

Links

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

Richard K. Guy, The Second Strong Law of Small Numbers, Math. Mag, Vol. 63, No. 1 (1990), pp. 3-20.

Example

629 is a term of the sequence because it is odd and divisible by 17 (= 6+2+9).

Maple

s:=proc(n) local N:N:=convert(n, base, 10):sum(N[j], j=1..nops(N)) end:p:=proc(n) if floor(n/s(n))=n/s(n) then n else fi end: seq(p(2*n-1), n=1..530);

Mathematica

Select[Range[1, 999, 2], Divisible[#, Total[IntegerDigits[#]]]&] (* Harvey P. Dale, Aug 22 2011 *)

Prog

(PARI) isok(n) = (n%2) && !(n % sumdigits(n)); \\ Michel Marcus, Sep 19 2017

Crossrefs

Cf. A005349, A101814.

Sequence in context: A030142 A179085 A076185 * A134719 A373509 A273519

Adjacent sequences: A101810 A101811 A101812 * A101814 A101815 A101816

Keyword

nonn,base

Author

Emeric Deutsch, Dec 16 2004

Extensions

Edited by Charles R Greathouse IV, Aug 03 2010

Status

approved