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A110539
Diagonal sums of A110537 viewed as a number triangle.
2
1, 1, 2, 3, 4, 5, 8, 10, 15, 23, 35, 58, 101, 193, 381, 817, 1820, 4298, 10550, 27037, 71715, 197062, 558923, 1635948, 4932931, 15313467, 48883315, 160311731, 539527417, 1861545528, 6578404569, 23788920636, 87961893345, 332339327570
OFFSET
1,3
LINKS
FORMULA
a(n) = Sum_{k=1..floor((n+1)/2)} Sum_{j=1..min(n-2k+2, k)} ceiling(j^(n-2k+2)/(n-2k+2)^j)*ceiling(j^k/k^j).
MATHEMATICA
A110539[n_] := Sum[Sum[ Ceiling[j^(n - 2*k + 2)/(n - 2*k + 2)^j] *Ceiling[j^k/k^j], {j, 1, Min[n - k + 1, k]}], {k, 1, Floor[n/2]}];
Table[A110539[n], {n, 1, 50}] (* G. C. Greubel, Aug 31 2017 *)
PROG
(PARI) a(n)=sum(k=1, floor((n+1)/2), sum(j=1, min(n-2*k+2, k), ceil(j^(n-2*k+2)/(n-2*k+2)^j)*ceil(j^k/k^j))) \\ G. C. Greubel, Aug 31 2017
CROSSREFS
Sequence in context: A373015 A039875 A206555 * A222297 A211981 A019997
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Jul 25 2005
STATUS
approved