A258914 Numbers k such that A258913(k) > k.

12, 18, 24, 31, 32, 42, 48, 54, 56, 60, 72, 80, 84, 90, 96, 98, 104, 108, 114, 120, 126, 128, 132, 140, 144, 152, 156, 168, 180, 182, 186, 192, 210, 216, 224, 228, 234, 240, 248, 252, 264, 270, 272, 280, 288, 294, 308, 312, 320, 324, 336, 342, 360, 372, 384

Offset

1,1

Comments

The first k of the form k = 6m-1 in this sequence is 86831.

What can be said about the asymptotic distribution of this set? If f(x) is the count of members not exceeding x, how does f behave as x tends to infinity?

Links

Giovanni Resta, Table of n, a(n) for n = 1..10000

Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).

Mathematics Stack Exchange, A number n which is the sum of all numbers k with sigma(k)=n?

Prog

(PARI) is_a(n)=sum(k=1, n, if(sigma(k)==n, k))>n
(PARI) is(k) = vecsum(invsigma(k)) > k; \\ Amiram Eldar, Dec 19 2024, using Max Alekseyev's invphi.gp

Crossrefs

Cf. A258913, A000203, A085790.

Sequence in context: A091013 A348715 A159886 * A241646 A181941 A206449

Adjacent sequences: A258911 A258912 A258913 * A258915 A258916 A258917

Keyword

nonn

Author

Jeppe Stig Nielsen, Jun 14 2015

Status

approved