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A114068
sigma(n) + phi(n) is a fourth power.
1
110, 125, 609, 2047, 4895, 9819, 10149, 10367, 18974, 31269, 37032, 40662, 42032, 44238, 44835, 48125, 51459, 51535, 52487, 77425, 90090, 116633, 129846, 137865, 145299, 146566, 151438, 159565, 161614, 162334, 207710, 307327, 357116
OFFSET
1,1
LINKS
EXAMPLE
sigma(110) + phi(110) = 256 = 4^4.
PROG
(PARI) isok(n) = ispower(sigma(n) + eulerphi(n), 4); \\ Michel Marcus, Jan 09 2014
CROSSREFS
Cf. A065387, subsequence of A062784.
Sequence in context: A274944 A275343 A059469 * A073494 A073488 A244389
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved