Search: id:A161184 Results 1-1 of 1 results found. %I A161184 %S A161184 1,2,4,6,3,6,9,3,6,3,9,6,9,9,3,9,6,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, %T A161184 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, %U A161184 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9 %N A161184 Digital roots of highly composite numbers (A002182). %C A161184 It appears that a significant number of highly composite numbers have 9 as their digital root. %C A161184 a(n)=9 for n>17 because for those n, the highly composite number A002182(n) is divisible by 9. [From T. D. Noe (noe(AT)sspectra.com), Jul 28 2009] %F A161184 a(n)=A010888(A140645(n)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 15 2009] %e A161184 7560 is a highly composite number whose digital root is 9. %p A161184 read("transforms3"): L := BFILETOLIST("b002182.txt") : A007953 := proc(n) add(d,d=convert(n,base,10)) ; end: A010888 := proc(n) local a ; a := A007953(n) ; while a > 9 do a := A007953(a) ; od; a; end: for i from 1 to 200 do printf("%d,", A010888(op(i,L))) ; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 15 2009] %Y A161184 Cf. A002182 %Y A161184 Sequence in context: A104492 A075075 A088178 this_sequence A140645 A117532 A057336 %Y A161184 Adjacent sequences: A161181 A161182 A161183 this_sequence A161185 A161186 A161187 %K A161184 nonn,base %O A161184 1,2 %A A161184 Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Jun 05 2009 %E A161184 Extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 15 2009 Search completed in 0.001 seconds