A362550 Number of even nontotients less than 10^n.

0, 13, 210, 2627, 29747, 319817, 3365629, 34962092, 360152096, 3688820638

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Example

a(1) = 0 since 2, 4, 6, and 8 are terms of A002202.
a(2) = 13 since there are 13 even nontotients less than 100, and they are 14,26,34,38,50,62,68,74,76,86,90,94 and 98.

Prog

(PARI) a(n)=sum(k=1, 10^n\2, !istotient(2*k)) \\ Charles R Greathouse IV, Apr 25 2023

Crossrefs

Cf. A002202, A005277, A072077.

Sequence in context: A145270 A296671 A196328 * A340431 A251093 A132542

Adjacent sequences: A362547 A362548 A362549 * A362551 A362552 A362553

Keyword

nonn,more

Author

Robert G. Wilson v, Apr 24 2023

Extensions

a(8)-a(10) from Charles R Greathouse IV, Apr 25 2023

Status

approved