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A008603
Multiples of 21.
11
0, 21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, 273, 294, 315, 336, 357, 378, 399, 420, 441, 462, 483, 504, 525, 546, 567, 588, 609, 630, 651, 672, 693, 714, 735, 756, 777, 798, 819, 840, 861, 882, 903, 924, 945, 966, 987
OFFSET
0,2
COMMENTS
Sum of the numbers from 3*(n-1) to 3*(n+1). - Bruno Berselli, Oct 25 2018
FORMULA
G.f.: 21*x/(x-1)^2. - Vincenzo Librandi, Jun 10 2013
MATHEMATICA
Range[0, 1500, 21] (* Vladimir Joseph Stephan Orlovsky, Jun 01 2011 *)
CoefficientList[Series[21 x / (x - 1)^2, {x, 0, 60}], x] (* Vincenzo Librandi, Jun 10 2013 *)
PROG
(PARI) a(n)=21*n \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
Sequence in context: A037978 A089059 A114384 * A235497 A086794 A001682
KEYWORD
nonn,easy
STATUS
approved