A174136 - OEIS

A174136

Partial sums of A003087.

1, 2, 4, 10, 41, 343, 6327, 249995, 20536020, 3445474030, 1169394086932, 798731069436512, 1094825607339329108, 3006942191342795594938, 16533858553282474307626008, 181924651566316766693192987410

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OFFSET

0,2

COMMENTS

Partial sums of number of acyclic digraphs with n unlabeled nodes; equivalently partial sums of the number of equivalence classes of n X n real (0,1)-matrices with all eigenvalues positive, up to conjugation by permutations. The subsequence of primes in this partial sum begins: 2, 41, no more through a(18).

LINKS

Table of n, a(n) for n=0..15.

FORMULA

a(n) = SUM[i=0..n] A003087(i).

CROSSREFS

Cf. A003087, A003024.

Sequence in context: A159860 A013549 A184253 * A125805 A344790 A028404

Adjacent sequences: A174133 A174134 A174135 * A174137 A174138 A174139

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Mar 09 2010

STATUS

approved