A056763 Number of x integers between 2^(n-1) and 2^n for which d(x)^3 > x holds, i.e., cube of number of divisors of x exceeds the number x and binary size of x is n.

1, 2, 4, 6, 11, 24, 30, 60, 110, 137, 248, 399, 491, 801, 1146, 1386, 1988, 2525, 2914, 3637, 4081, 4334, 4649, 4579, 4305, 3867, 3211, 2467, 1730, 1119, 592, 272

Offset

1,2

Links

Table of n, a(n) for n=1..32.

Example

a(5)=11 because 11 integers occur between 1 + 2^4 = 17 and 2^ 5=32 for which the cube of number of divisors exceeds the number itself: {18,20,21,22,24,25,26,27,28,30,32} Between 2^28 and 2^29, 1730 such numbers occur.

Crossrefs

Cf. A000005, A029837, A034884, A035033-A035035, A056757-A056767.

Sequence in context: A084353 A084979 A049914 * A190071 A189498 A129567

Adjacent sequences: A056760 A056761 A056762 * A056764 A056765 A056766

Keyword

nonn,more

Author

Labos Elemer, Aug 16 2000

Extensions

a(30)-a(32) from Sean A. Irvine, May 06 2022

Status

approved