|
Search: id:A101813
|
|
|
| A101813 |
|
Odd Niven (or Harshad) numbers: odd numbers that are divisible by the sum of their digits. |
|
+0
2
|
|
| 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
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
REFERENCES
|
R. K. Guy, The second strong law of small numbers. Math. Mag. 63 (1990), no. 1, 3-20.
D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, 171.
|
|
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);
|
|
CROSSREFS
|
Cf. A005349, A101814.
Sequence in context: A003219 A030142 A076185 this_sequence A134719 A099995 A100028
Adjacent sequences: A101810 A101811 A101812 this_sequence A101814 A101815 A101816
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 16 2004
|
|
|
Search completed in 0.002 seconds
|
