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 A191599 Numbers n such that n does not divide Ramanujan's tau(n). 2
 11, 13, 17, 19, 22, 23, 26, 29, 31, 33, 34, 37, 38, 39, 41, 43, 44, 46, 47, 51, 52, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, 68, 69, 71, 73, 74, 76, 77, 78, 79, 82, 83, 85, 86, 87, 89, 93, 94, 95, 97, 99, 101, 102, 103, 104, 106, 107, 109, 110, 111, 113, 114 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The sequence has his first 45 terms in common with A068191. The sequence is a subsequence of A068191. Complement of A063938. - Omar E. Pol, Aug 28 2011 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 B. Ramakrishnan and Brundaban Sahu, Rankin-Cohen brackets and Van der Pol-type identities for the Ramanujan's tau function, arXiv:0711.3512 [math.NT], 2007, pp. 14. See Corollary 2.11 EXAMPLE For n=1, a(1)=11 since 11 does not divide tau(11) = 534612. MAPLE with(numtheory): tn := proc(n) modp(-840*sum(k^4*sigma(k)*sigma(n-k), k=1..n-1), n); end; ser := proc(a, b) local n, lis; lis := []; for n from a to b do if tn(n) <> 0 then lis := [op(lis), n]; fi; od; lis; end; MATHEMATICA Select[Range[120], !Divisible[RamanujanTau[#], #]&] (* Jean-François Alcover, Nov 29 2017 *) CROSSREFS Cf. A000594, A068191. Sequence in context: A333237 A048388 A068191 * A084374 A063193 A056758 Adjacent sequences:  A191596 A191597 A191598 * A191600 A191601 A191602 KEYWORD nonn AUTHOR Luis H. Gallardo, Jun 08 2011 STATUS approved

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Last modified June 21 19:12 EDT 2021. Contains 345365 sequences. (Running on oeis4.)