1,1

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

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

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

(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)

Cf. A000010, A039697.

Sequence in context: A257496 A162616 A153362 * A175652 A110833 A225808

Adjacent sequences: A039785 A039786 A039787 * A039789 A039790 A039791

nonn,more

Olivier Gérard

approved