%I A022266
%S A022266 0,4,17,39,70,110,159,217,284,360,445,539,642,754,875,1005,
%T A022266 1144,1292,1449,1615,1790,1974,2167,2369,2580,2800,3029,
%U A022266 3267,3514,3770,4035,4309,4592,4884,5185,5495,5814,6142
%N A022266 n*(9n-1)/2.
%C A022266 Write 0,1,2,3,4,... in a triangular spiral, then a(n) is the sequence 
               found by reading the line from 0 in the direction 0,4,... - Floor 
               van Lamoen (fvlamoen(AT)hotmail.com), Jul 21 2001. The spiral begins:
%C A022266 ..........15
%C A022266 ........16..14
%C A022266 ......17..3...13
%C A022266 ....18..4...2...12
%C A022266 ..19..5...0...1...11
%C A022266 20..6...7...8...9...10
%F A022266 a(n)=C(9*n,2)/9,n>=0 - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Jan 02 2007
%F A022266 a(n)=A049452(n)-A000326(n). - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Jun 12 2007
%F A022266 a(n)=9*n+a(n-1)-14 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), 
               Nov 12 2009]
%e A022266 For n=2, a(2)=9*2+0-14=4; n=3, a(3)=9*3+4-14=17; n=4, a(4)=9*4+17-14=39 
               [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 12 2009]
%p A022266 [seq(binomial(9*n,2)/9,n=0..37)]; - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Jan 02 2007
%p A022266 seq(n*(6*n-1)-n*(3*n-1)/2,n=0..37); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Jun 12 2007
%t A022266 s=0;lst={s};Do[s+=n++ +4;AppendTo[lst, s], {n, 0, 7!, 9}];lst [From Vladimir 
               Orlovsky (4vladimir(AT)gmail.com), Nov 16 2008]
%Y A022266 Cf. A051682.
%Y A022266 Sequence in context: A031092 A120884 A041859 this_sequence A145995 A018973 
               A162148
%Y A022266 Adjacent sequences: A022263 A022264 A022265 this_sequence A022267 A022268 
               A022269
%K A022266 nonn,new
%O A022266 0,2
%A A022266 N. J. A. Sloane (njas(AT)research.att.com).