A240990 - OEIS

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A240990

Smallest integer m such that A240923(m) = n.

1, 6, 15, 10, 14, 72, 22, 26, 42, 34, 38, 588, 46, 240, 78, 58, 62, 1456, 92, 74, 114, 82, 86, 1764, 70, 760, 640, 106, 195, 792, 108, 122, 186, 172, 134, 432, 110, 146, 222, 816, 158, 1656, 130, 396, 258, 178, 411, 3000, 154, 194, 342, 202, 206, 11904, 170

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..54.

EXAMPLE

sigma(6)/6 = 2/1 = (sigma(1)+1)/1, where sigma is A000203, so A240923(6)=1, and it is the smallest such integer, so a(1)=6.

PROG

(PARI) a240923(n) = my(ab = sigma(n)/n); numerator(ab) - sigma(denominator(ab));

a(n) = my(k = 1); while(a240923(k) != n, k++); k;

CROSSREFS

Cf. A000203, A017665, A017666, A240923.