A290242 The number of noncototient numbers <= 10^n.

1, 8, 98, 963, 10527, 110786, 1128160, 11355049, 113482572, 1129598504

Offset

1,2

Comments

a(5)-a(8) were taken from the paper by Pomerance and Yang.

a(9)-a(10) were taken from the paper Pollack and Pomerance.

Links

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

Carl Pomerance and Hee-Sung Yang, Variant of a theorem of Erdős on the sum-of-proper-divisors function, Mathematics of Computation, Vol. 83, No. 288 (2014), pp. 1903-1913.

Paul Pollack and Carl Pomerance, Some problems of Erdős on the sum-of-divisors function, Transactions of the American Mathematical Society, Series B Vol. 3, No. 1 (2016), pp. 1-26.

Crossrefs

Cf. A005278.

Sequence in context: A303409 A264168 A116287 * A116229 A099150 A199029

Adjacent sequences: A290239 A290240 A290241 * A290243 A290244 A290245

Keyword

nonn,more

Author

Amiram Eldar, Jul 24 2017

Status

approved