OFFSET
0,3
REFERENCES
Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 166.
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..10000
EXAMPLE
a(0) = phi(0^2 + 1) = phi(1) = 1.
MATHEMATICA
Table[EulerPhi[k^2 + 1], {k, 0, 100}]
PROG
(PARI) a(n) = eulerphi(n^2+1); \\ Michel Marcus, Mar 10 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Mar 09 2020
STATUS
approved