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A039788 phi(a(n)) is equal to the product of (the sum of prime factors and the sum of exponents) of (a(n)). 0
9, 16, 35, 45, 150, 154, 234, 264 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term if it exists is greater than 10000000. - C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 29 2004

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

phi(45)=24, 45=3^2*5^1, (3+5)*(2+1)=24.

PROG

(PARI) for(n=1, 10000000, f=factor(n); l=#f[, 1]; if(eulerphi(n)==sum(i=1, l, f[i, 1])*sum(i=1, l, f[i, 2]), print1(n, ", "))) (Ronaldo)

CROSSREFS

Cf. A000010, A039697.

Sequence in context: A257496 A162616 A153362 * A175652 A110833 A225808

Adjacent sequences:  A039785 A039786 A039787 * A039789 A039790 A039791

KEYWORD

nonn,more

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified September 21 14:54 EDT 2020. Contains 337272 sequences. (Running on oeis4.)