Search: id:A129754 Results 1-1 of 1 results found. %I A129754 %S A129754 11,278,202040,107371882880,30324991112647875920960, %T A129754 2418916677393691552133618294938847890243982720, %U A129754 15390805926573768302084260548391044837412074858741153833336080616936611834819590898337488640 %N A129754 The natural numbers represented by their set theoretic Von Neumann construction, where the empty set is replaced by '0', the left set bracket '{' is replaced by 1, the right bracket '}' is replaced by 2, the set construct contents are ordered by increasing cardinality and the final number is interpreted in base 3. %H A129754 I.N. Galidakis, Home Page %F A129754 S(n)=n union {n} %e A129754 a(0)=0=0[3]=0, a(1)={0}=102[3]=11, a(2)={0,{0}}=101022[3]=278, etc %p A129754 N:=proc(n) local i,s,l,r,data; s:=`0`;l:=`1`;r:=`2`; if n>0 then for i from 1 to n-1 do s:=cat(s,l,s,r); od; s:=cat(l,s,r); fi; data:=sscanf(s, `%d`); RETURN(data[1]); end: b3tob10:=proc(n) local i,nl,sl,suma; if n=0 then suma:=0; else sl:=convert(n,base,10); nl:=convert(sl, base,3,10); suma:=sum(nl[i]*10^(i-1),i=1..nops(nl)); fi; RETURN(suma); end: for n from 0 to 7 do b3tob10(N(n)); od; %Y A129754 Cf. A129751. %Y A129754 Sequence in context: A160195 A062210 A049080 this_sequence A103547 A166182 A064758 %Y A129754 Adjacent sequences: A129751 A129752 A129753 this_sequence A129755 A129756 A129757 %K A129754 easy,nonn %O A129754 0,1 %A A129754 I.N. Galidakis (jgal(AT)ath.forthnet.gr), May 14 2007 Search completed in 0.001 seconds