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 A247034 Smallest integer x such that the number of integers y sigma(x)/x is exactly n. 1
 1, 3, 10, 5, 9, 7, 15, 32, 132, 11, 21, 13, 44, 70, 52, 17, 25, 19, 38, 33, 198, 23, 35, 46, 39, 76, 234, 29, 220, 31, 224, 62, 51, 136, 260, 37, 57, 55, 74, 41, 1170, 43, 196, 82, 69, 47, 10440, 154, 222, 94, 520, 53, 744, 148, 77, 190, 87, 59, 182, 61, 93 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Conjecture: a(n) exists for all n. LINKS Amiram Eldar, Table of n, a(n) for n = 0..421 PROG (PARI) lista(nn) = {v = vector(nn, n, sigma(n)/n); vmore = vector(nn+1); for (n=1, nn, nb = sum(i=1, n, v[i] > v[n]); if (vmore[nb+1] == 0, vmore[nb+1] = n); ); for (i=1, #vmore, if (!vmore[i], break, print1(vmore[i], ", "))); } CROSSREFS Cf. A000203 (sigma), A004394 (superabundant), A017665 and A017666 (sigma(n)/n). Cf. A247015. Sequence in context: A111229 A100984 A045985 * A275511 A035411 A033478 Adjacent sequences:  A247031 A247032 A247033 * A247035 A247036 A247037 KEYWORD nonn AUTHOR Michel Marcus, Sep 10 2014 STATUS approved

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Last modified December 7 00:36 EST 2019. Contains 329812 sequences. (Running on oeis4.)