|
|
A055264
|
|
Possible values of A055263; numbers equal to 0, 1, 3 or 6 modulo 9.
|
|
5
|
|
|
0, 1, 3, 6, 9, 10, 12, 15, 18, 19, 21, 24, 27, 28, 30, 33, 36, 37, 39, 42, 45, 46, 48, 51, 54, 55, 57, 60, 63, 64, 66, 69, 72, 73, 75, 78, 81, 82, 84, 87, 90, 91, 93, 96, 99, 100, 102, 105, 108, 109, 111, 114, 117, 118, 120, 123, 126, 127, 129, 132, 135, 136, 138, 141
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
The terms are the possible digit sums of a triangular number. - Amarnath Murthy, Jan 09 2002
|
|
LINKS
|
|
|
FORMULA
|
a(n) = a(n-4) + 9 = 9*floor(n/4) + (n mod 4)*(1 + (n mod 4))/2.
G.f.: x(1+2x+3x^2+3x^3)/((1-x)^2(1+x)(1+x^2)). - R. J. Mathar, Sep 30 2008
|
|
MATHEMATICA
|
Select[Range[0, 200], MemberQ[{0, 1, 3, 6}, Mod[#, 9]]&] (* Harvey P. Dale, Apr 10 2014 *)
#+{0, 1, 3, 6}&/@(9*Range[0, 20])//Flatten (* Harvey P. Dale, Jun 03 2019 *)
|
|
PROG
|
(Python)
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|