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A069952 Numbers n such that (n+1)*phi(n) is a perfect square. 0
8, 26, 44, 48, 63, 485, 636, 866, 960, 1034, 1351, 1407, 1520, 3970, 4912, 7580, 8749, 12935, 14282, 19601, 20824, 23103, 36480, 43680, 44505, 48599, 49004, 58620, 63000, 72896, 75842, 85696, 90167, 97469, 108240, 122316, 127007, 134135 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

If k>1 k*phi(k) is not a perfect square. If p is prime (p-1)*phi(p) is a perfect square.

CROSSREFS

Sequence in context: A200785 A120743 A063560 * A031085 A031307 A122854

Adjacent sequences:  A069949 A069950 A069951 * A069953 A069954 A069955

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 27 2002

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Last modified February 14 06:20 EST 2012. Contains 205570 sequences.