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 A066284 a(n) = A066135(4*n). 5
 34, 84, 34, 84, 34, 194, 34, 84, 34, 84, 34, 228, 34, 84, 34, 84, 34, 194, 34, 84, 34, 84, 34, 228, 34, 84, 34, 84, 34, 194, 34, 84, 34, 84, 34, 386, 34, 84, 34, 84, 34, 194, 34, 84, 34, 84, 34, 228, 34, 84, 34, 84, 34, 194, 34, 84, 34, 84, 34, 228, 34, 84, 34, 84, 34, 194 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) <= 2p, where p = A002586(4n) is the least prime factor of (1 + 16^n). (See the Comment in A066135.) - Jonathan Sondow, Nov 23 2012 LINKS Michael De Vlieger, Table of n, a(n) for n = 1..1000 FORMULA a(n) = Min{x : sigma_4n(x) mod x = 0, x > 1} EXAMPLE First 3 terms correspond to entries of other sequences as follows: a(1)=A046763(2), a(2)=A055712(2), a(3)=A055716(2). From Michael De Vlieger, Jul 17 2017: (Start) First position of values, with observations pertaining to values for 1 <= n <= 3000:     Value   Position   Observations:     --------------------------------        34     1        All odd.        84     2        In A047235.       194     6        In A017593.       228    12       386    36      1282    72      1538   144      3084   288    147468   576      1956   864   1046532  1152     24578  2304      3252  2880 (End) MATHEMATICA Table[m = 2; While[Mod[DivisorSigma[4 n, m], m] > 0, m++]; m, {n, 66}] (* Michael De Vlieger, Jul 17 2017 *) PROG (PARI) a(n) = {n *= 4; my(m = 2); while (sigma(m, n) % m, m++); m; } \\ Michel Marcus, Oct 02 2016 CROSSREFS Cf. A066135, A046761, A046762, A046763, A055709-A055717, A007691, A001159. Sequence in context: A066944 A044172 A044553 * A036199 A092223 A046764 Adjacent sequences:  A066281 A066282 A066283 * A066285 A066286 A066287 KEYWORD nonn AUTHOR Labos Elemer, Dec 11 2001 STATUS approved

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Last modified June 26 16:18 EDT 2022. Contains 354885 sequences. (Running on oeis4.)