%I #19 Apr 19 2024 02:26:46
%S 21,45,69,93,117,141,165,189,213,237,261,285,309,333,357,381,405,429,
%T 453,477,501,525,549,573,597,621,645,669,693,717,741,765,789,813,837,
%U 861,885,909,933,957,981,1005,1029,1053,1077,1101,1125,1149,1173,1197
%N a(n) = 24*n + 21.
%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%t Range[21, 2000, 24] (* _Vladimir Joseph Stephan Orlovsky_, Jun 14 2011 *)
%t 24*Range[0,60]+21 (* or *) LinearRecurrence[{2,-1},{21,45},60] (* _Harvey P. Dale_, Oct 06 2015 *)
%o (PARI) a(n)=24*n+21 \\ _Charles R Greathouse IV_, Jun 14 2011
%Y Cf. A004771.
%K easy,nonn
%O 0,1
%A _Alexandre Wajnberg_, Jan 29 2005