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Search: a175177 -id:a175177
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Number of antichains in divisor lattice D(n).
+10
23
2, 3, 3, 4, 3, 6, 3, 5, 4, 6, 3, 10, 3, 6, 6, 6, 3, 10, 3, 10, 6, 6, 3, 15, 4, 6, 5, 10, 3, 20, 3, 7, 6, 6, 6, 20, 3, 6, 6, 15, 3, 20, 3, 10, 10, 6, 3, 21, 4, 10, 6, 10, 3, 15, 6, 15, 6, 6, 3, 50, 3, 6, 10, 8, 6, 20, 3, 10, 6, 20, 3, 35, 3, 6, 10, 10, 6, 20, 3, 21, 6, 6, 3, 50, 6, 6, 6, 15, 3, 50, 6
OFFSET
1,1
COMMENTS
The divisor lattice D(n) is the lattice of the divisors of the natural number n.
The empty set is counted as an antichain in D(n).
a(n) = gamma(n+1) where gamma is degree of cardinal completeness of Łukasiewicz n-valued logic. - Artur Jasinski, Mar 01 2010
REFERENCES
Alexander S. Karpenko, Lukasiewicz's Logics and Prime Numbers, Luniver Press, Beckington, 2006. See Table I p. 113.
FORMULA
a(n) = A285573(n) + 1. - Gus Wiseman, Aug 24 2018
MATHEMATICA
nn=200;
stableSets[u_, Q_]:=If[Length[u]===0, {{}}, With[{w=First[u]}, Join[stableSets[DeleteCases[u, w], Q], Prepend[#, w]&/@stableSets[DeleteCases[u, r_/; r===w||Q[r, w]||Q[w, r]], Q]]]];
Table[Length[stableSets[Divisors[n], Divisible]], {n, nn}] (* Gus Wiseman, Aug 24 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 17 2004
EXTENSIONS
More terms from John W. Layman, Aug 20 2004
STATUS
approved
a(n)=Values of cardinality of rooted trees CRT for successive primes.
+10
4
1, 1, 1, 2, 1, 5, 1, 1, 1, 1, 1, 2, 4, 6, 1, 1, 2, 9, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 5, 6, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 16, 1, 9, 2, 1, 1, 1, 1, 1, 7, 1, 19, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 6, 3, 1, 1, 2, 1, 11, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1
OFFSET
1,4
REFERENCES
Karpenko A.S. 2006. Lukasiewicz's Logics and Prime Numbers (English translation).
Karpenko A.S. 2000. Lukasiewicz's Logics and Prime Numbers (Russian).
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Mar 01 2010
STATUS
approved
Primes for which value of CRT (Cardinality of rooted tree) is equal to 1.
+10
1
2, 3, 5, 11, 17, 19, 23, 29, 31, 47, 53, 67, 71, 79, 83, 89, 97, 101, 103, 107, 127, 131, 137, 139, 149, 151, 163, 167, 173, 179, 191, 199
OFFSET
1,1
COMMENTS
Primes p = Prime(x) such that A175178(x)=1.
REFERENCES
Karpenko A.S. 2006. Lukasiewicz's Logics and Prime Numbers (English translation).
Karpenko A.S. 2000. Lukasiewicz's Logics and Prime Numbers (Russian).
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Mar 01 2010
STATUS
approved
a(n) = number of iterations in the sequence of classes of prime numbers for prime(n).
+10
0
0, 0, 0, 0, 0, 1, 1, 2, 2, 2, 3, 2, 2, 3, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 4, 4, 4, 4, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 6, 5, 4, 4, 4, 4, 4, 6, 4, 5, 4, 5, 4, 5, 5, 4, 4, 4, 4, 5, 6, 5, 4, 6, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8
OFFSET
2,8
REFERENCES
Alexander S. Karpenko, Lukasiewicz's Logics and Prime Numbers, Luniver Press, Beckington, 2006, pp. 98-102.
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Mar 01 2010
EXTENSIONS
Edited, corrected and extended by Arkadiusz Wesolowski, Jan 19 2013
STATUS
approved

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