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A069822 n such there is at least one x<n such that sigma(x)=sigma(n). 7
11, 15, 17, 23, 25, 26, 31, 35, 38, 39, 41, 46, 47, 51, 53, 55, 56, 58, 59, 62, 65, 69, 70, 71, 75, 77, 78, 79, 82, 83, 87, 89, 92, 94, 95, 97, 103, 107, 110, 113, 115, 116, 118, 119, 122, 123, 124, 125, 127, 130, 131, 135, 139, 140, 141, 142, 143, 145, 151, 153 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

PROG

(PARI) for(s=1, 200, if(prod(i=1, s-1, sigma(i)-sigma(s))==0, print1(s, ", ")))

CROSSREFS

Sequence in context: A139065 A186404 A111322 * A116999 A053675 A031944

Adjacent sequences:  A069819 A069820 A069821 * A069823 A069824 A069825

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 28 2002

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Last modified February 16 18:43 EST 2012. Contains 205939 sequences.