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A067051 The smallest k>1 such that k divides sigma(k*n) is equal to 3. 2
2, 8, 18, 32, 49, 50, 72, 98, 128, 162, 169, 196, 200, 242, 288, 338, 361, 392, 441, 450, 512, 578, 648, 676, 722, 784, 800, 882, 961, 968, 1058, 1152, 1225, 1250, 1352, 1369, 1444, 1458, 1521, 1568, 1682, 1764, 1800, 1849, 1922, 2048, 2178, 2312, 2450, 2592 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The smallest m>1 such that m divides sigma(m*n) is 2, 3 or 6.

LINKS

Table of n, a(n) for n=1..50.

PROG

(PARI) isok(n) = (sigma(2*n) % 2) && !(sigma(3*n) % 3); \\ Michel Marcus, Dec 26 2013

CROSSREFS

Appears to be the same sequence as A074629. - Ralf Stephan, Aug 18 2004.

Sequence in context: A063581 A293296 A055044 * A074629 A209303 A001105

Adjacent sequences:  A067048 A067049 A067050 * A067052 A067053 A067054

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Jul 26 2002

STATUS

approved

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Last modified December 6 14:47 EST 2019. Contains 329806 sequences. (Running on oeis4.)