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A178962 Partial sums of number of functors of degree n from free Abelian groups to Abelian groups A007322. 0
1, 7, 46, 366, 3647, 44205, 630956, 10350572, 191704349, 3954598099, 89888942874, 2231742720730, 60083847852539, 1743321481158041, 54226970410827160, 1800062257926566488, 63512168752599139129, 2373501269897667585631 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Partial sums of partial sums of number of matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n (A120733). Partial sums of dimensions of the graded components of the Hopf algebra MQSym (Matrix quasi-symmetric functions). a(2) = 7 is the only prime through a(18).
LINKS
FORMULA
a(n) = SUM[i=1..n]] SUM[r>=0,s>=0] binomial(r*s+i-1,i)/2^(r+s+2).
EXAMPLE
a(3) = 1 + 6 + 39 = 46.
CROSSREFS
Sequence in context: A072948 A332852 A356827 * A203267 A319601 A352693
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Dec 31 2010
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)