%I A123860
%S A123860 4,6,7,8,9,9,10,10,11,11,12,12,12,13,13,13,14,14,14,15,15,15,15,16,16,
               16,
%T A123860 16,17,17,17,17,18,18,18,18,18,19,19,19,19,19,20,20,20,20,20,21,21,21,
               21,
%U A123860 21,21,22,22,22,22,22,22,23,23,23,23,23,23,24,24,24,24,24,24,24,25,25,
               25
%N A123860 Ceil( (7+sqrt(49+24*n))/2 ).
%D A123860 J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 
               2004; p. 742.
%p A123860 f:=n->ceil( (7+sqrt(49+24*n))/2 );
%Y A123860 Cf. A000703.
%Y A123860 Sequence in context: A006185 A021876 A005670 this_sequence A122817 A074764 
               A101087
%Y A123860 Adjacent sequences: A123857 A123858 A123859 this_sequence A123861 A123862 
               A123863
%K A123860 nonn
%O A123860 -2,1
%A A123860 N. J. A. Sloane (njas(AT)research.att.com), Nov 19 2006