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Search: id:A129754
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| A129754 |
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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. |
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+0
2
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| 11, 278, 202040, 107371882880, 30324991112647875920960, 2418916677393691552133618294938847890243982720, 15390805926573768302084260548391044837412074858741153833336080616936611834819590\ 898337488640
(list; graph; listen)
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OFFSET
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0,1
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LINKS
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I.N. Galidakis, Home Page
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FORMULA
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S(n)=n union {n}
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EXAMPLE
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a(0)=0=0[3]=0, a(1)={0}=102[3]=11, a(2)={0,{0}}=101022[3]=278, etc
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MAPLE
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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;
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CROSSREFS
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Cf. A129751.
Adjacent sequences: A129751 A129752 A129753 this_sequence A129755 A129756 A129757
Sequence in context: A108519 A062210 A049080 this_sequence A103547 A064758 A030428
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KEYWORD
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easy,nonn
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AUTHOR
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I.N. Galidakis (jgal(AT)ath.forthnet.gr), May 14 2007
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