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 A362643 Number of labeled magmas with n elements satisfying the equations (xy)y = x and x(yz) = xy. 4
 1, 1, 2, 10, 94, 1636, 49636, 2489824, 204626528, 27296455456, 5930440245856, 2144594499551296, 1333437360189448768, 1510196144261999035648, 3333925936841219018864384, 15357830414682103475484461056, 155003843551785210349182746546176 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Andrew Howroyd, Table of n, a(n) for n = 0..50 FORMULA E.g.f.: Sum_{k>=0} log(B(k,x))^k/k! where B(k,x) = Sum_{j>=0} A000085(j)^k*x^j/j!. PROG (PARI) B(n, k)=my(p=serlaplace(exp(x + x^2/2 + O(x*x^n)))); sum(j=0, n, polcoef(p, j)^k*x^j/j!, O(x*x^n)) seq(n)=Vec(serlaplace(sum(k=0, n, log(B(n-k+1, k))^k/k!))) CROSSREFS Cf. A000085, A362383, A362386, A362642 (isomorphism classes). Sequence in context: A355782 A103436 A182173 * A160940 A346649 A355780 Adjacent sequences: A362640 A362641 A362642 * A362644 A362645 A362646 KEYWORD nonn AUTHOR Andrew Howroyd, Apr 28 2023 STATUS approved

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Last modified August 4 13:44 EDT 2024. Contains 374923 sequences. (Running on oeis4.)