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A063753 Cototient(n) is a square and sets a new record for squares. 2
2, 6, 21, 24, 54, 96, 189, 216, 345, 384, 420, 796, 864, 1332, 1536, 1680, 2340, 3300, 3780, 5328, 6144, 6516, 6720, 8260, 8484, 9360, 10500, 13200, 14532, 15120, 18340, 19476, 20580, 24576, 26064, 26628, 26880, 29700, 33396, 33936, 34020 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,275

PROG

(PARI)a=0; for(n=1, 7000, x=n-eulerphi(n); if(issquare(x), b=x; if(b>a, a=b; print(n))))

(PARI) { n=0; a=0; for (m=1, 10^9, if (issquare(b=m - eulerphi(m)), if (b>a, a=b; write("b063753.txt", n++, " ", m); if (n==275, break))) ) } [From Harry J. Smith, Aug 29 2009]

CROSSREFS

Cf. A051953.

Sequence in context: A103160 A242819 A126099 * A066893 A004192 A104143

Adjacent sequences:  A063750 A063751 A063752 * A063754 A063755 A063756

KEYWORD

easy,nonn

AUTHOR

Jason Earls (zevi_35711(AT)yahoo.com), Aug 11 2001

EXTENSIONS

More terms from Dean Hickerson, Aug 22 2001

STATUS

approved

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Last modified March 23 22:30 EDT 2017. Contains 283985 sequences.