A176527 Partial sums of A006058.

1, 2, 5, 21, 166, 2277, 49901, 1675904, 84239935, 6231045077, 668949067432, 103005162942955, 22511886374045653, 6918461813753405930, 2965189776573865320121, 1759287329824925168339697, 1435531006280642249195752862, 1601571709194974043628781397985, 2430449338115875591262479128994073

Offset

0,2

Comments

Partial sums of number of connected labeled topologies with n points. The subsequence of primes in this partial sum begins: 2, 5, and then what?

Links

Table of n, a(n) for n=0..18.

Formula

a(n) = Sum_{i=0..n} A006058(i) = Sum_{i=0..n} Sum_{k=0..i-1} C(i, k)*A000798(k) (for i>=1).

Mathematica

Cases[Import["https://oeis.org/A006058/b006058.txt", "Table"], {_, _}][[All, 2]] // Accumulate (* Jean-François Alcover, Jan 01 2020 *)

Crossrefs

Cf. A000798, A006058.

Sequence in context: A144271 A193189 A358316 * A117261 A108021 A162437

Adjacent sequences: A176524 A176525 A176526 * A176528 A176529 A176530

Keyword

nonn

Author

Jonathan Vos Post, Apr 19 2010

Extensions

a(16)-a(18) from Jinyuan Wang, Feb 23 2020

Status

approved