Search: id:A060009 Results 1-1 of 1 results found. %I A060009 %S A060009 1,9,10,11,12,13,14,15,16,17,18,20,36,38,39,40,41,42,43,44,46,66,67,68, %T A060009 69,70,71,72,73,92,101,121,122,123,124,125,126,127,146,155,174,182,201, %U A060009 211,229,230,237,256,284,285,286,287,288,289,290,291,311,348,365,368 %N A060009 Ulam numbers with starting with 1 and 9. %D A060009 C. Pickover, Wonders of Numbers, Oxford University Press, NY, 2001, p. 185-186. %D A060009 Cf. A002858 %H A060009 C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," Zentralblatt review %F A060009 Ulam numbers are positive integers that can be expressed in just one way as the sum of two distinct earlier members of the sequence in increasing order. %e A060009 a(4)=11 is an Ulam number because 10 + 1 = 11, but 19 is not because there is more than one way to form 19 from summing previous sequence numbers, e.g. 18 + 1 and 10 + 9. %Y A060009 Cf. A002858. %Y A060009 Sequence in context: A020723 A107043 A023392 this_sequence A115843 A058365 A162789 %Y A060009 Adjacent sequences: A060006 A060007 A060008 this_sequence A060010 A060011 A060012 %K A060009 nonn %O A060009 1,2 %A A060009 Jason Earls (zevi_35711(AT)yahoo.com), Mar 16 2001 Search completed in 0.001 seconds