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%I #20 Jan 05 2013 09:08:07
%S 0,1,2,4,6,9,12,17,21,28,33,44,50,65,72,94,102,132,141,183,193,249,
%T 260,337,349,450,463,598,612,788,803,1034,1050,1347,1364,1749,1767,
%U 2257,2276,2903,2923,3715,3736,4738,4760,6015,6038,7613,7637,9595
%N Vertex number of a rectangular spiral which contains exactly between its edges the successive shells of the partitions of the positive integers.
%C First differences give A194451, the length of the edges of the spiral. For more information see A135010 and A138121.
%F a(2n-1) = A026905(n) + A000217(n) - n, if n >= 1.
%F a(2n) = A026905(n) + A000217(n), if n >= 1.
%Y Cf. A000041, A000217, A006128, A026905, A066186, A135010, A138121, A138879, A138880, A182703, A182994, A182995, A194451.
%K nonn
%O 0,3
%A _Omar E. Pol_, Nov 01 2011