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A079477
First prime after phi(prime(n)^2).
1
3, 7, 23, 43, 113, 157, 277, 347, 509, 821, 937, 1361, 1657, 1811, 2179, 2767, 3433, 3671, 4423, 4973, 5261, 6163, 6823, 7841, 9319, 10103, 10513, 11351, 11777, 12659, 16007, 17033, 18637, 19183, 22063, 22651, 24499, 26407, 27733, 29759, 31873, 32587, 36293
OFFSET
1,1
COMMENTS
The sequence always increases.
LINKS
FORMULA
a(n) = A151800(A036689(n)). - Michel Marcus, Mar 15 2023
EXAMPLE
p_3=5, phi(5^2)=phi(25)=20, therefore a(3)=23
MAPLE
a:= n-> nextprime(2*binomial(ithprime(n), 2)):
seq(a(n), n=1..44); # Alois P. Heinz, Mar 15 2023
MATHEMATICA
Prime[1+PrimePi[EulerPhi[Prime[Range[41]]^2]]] (* T. D. Noe, Nov 15 2006 *)
PROG
(PARI) forprime (p=2, 200, print1(nextprime(eulerphi(p^2))", "))
CROSSREFS
Sequence in context: A133434 A122870 A216816 * A014426 A054270 A058000
KEYWORD
nonn
AUTHOR
Jon Perry, Jan 15 2003
EXTENSIONS
Corrected by T. D. Noe, Nov 15 2006
STATUS
approved