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 A193139 Number of symmetric satins of order n. 2
 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 3, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 3, 0, 1, 0, 1, 1, 0, 0, 3, 0, 0, 1, 1, 0, 0, 1, 3, 1, 0, 0, 3, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 3, 0, 0, 1, 1, 1, 1, 0, 3, 0, 0, 0, 3, 1, 0, 1, 3, 0, 1, 1, 1, 1, 0, 1, 3, 0, 0, 1, 1, 0, 1, 0, 3, 3, 0, 0, 1, 0, 1, 1, 3, 0, 1, 1, 1, 1, 0, 1, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,22 LINKS B. Grünbaum and G. C. Shephard, Satins and twills: an introduction to the geometry of fabrics, Math. Mag., 53 (1980), 139-161. See Theorem 5. FORMULA a(n) = A157230(n) - 1. - Andrey Zabolotskiy, Dec 25 2018 MAPLE V:=proc(n) local j, i, t1, t2, al, even; t1:=ifactors(n)[2]; t2:=nops(t1); if (n mod 2) = 0 then even:=1; al:=t1[1][2]; else even:=0; al:=0; fi; j:=t2-even; if (al <= 1) then RETURN(2^(j-1)-1); fi; if (al = 2) then RETURN(2^j-1); fi; if (al >= 3) then RETURN(2^(j+1)-1); fi; end; [seq(V(n), n=3..120)]; CROSSREFS Cf. A193138, A193140, A157230. Sequence in context: A085393 A128980 A096693 * A083206 A069531 A035677 Adjacent sequences:  A193136 A193137 A193138 * A193140 A193141 A193142 KEYWORD nonn AUTHOR N. J. A. Sloane, Jul 16 2011 STATUS approved

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Last modified October 20 10:45 EDT 2019. Contains 328257 sequences. (Running on oeis4.)