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A353154
Sum of the even-indexed terms in the n-th row of the triangle A196020.
2
0, 0, 1, 0, 3, 0, 5, 0, 7, 1, 9, 0, 11, 3, 13, 0, 15, 5, 17, 0, 20, 7, 21, 0, 23, 9, 28, 0, 27, 11, 29, 0, 36, 13, 33, 1, 35, 15, 44, 0, 39, 17, 41, 3, 52, 19, 45, 0, 47, 21, 60, 5, 51, 23, 54, 0, 68, 25, 57, 7, 59, 27, 76, 0, 66, 29, 65, 9, 84, 31, 69, 0, 71, 33, 97, 11, 75, 36, 77, 0
OFFSET
1,5
COMMENTS
Conjecture: indices of zeros give A082662.
a(n) is the total number of steps in all even-indexed double-staircases of the diagram of A196020 with n levels.
a(n) is also the total number of steps in all even-indexed double-staircases of the diagram described in A335616 with n levels that have at least one step in the bottom level of the diagram.
The graph of the sum-of-divisors function A000203 is intermediate between the graph of A353149 and the graph of this sequence (see the Links section). - Omar E. Pol, May 13 2022
FORMULA
a(n) = A353149(n) - A000203(n).
a(n) = A209246(n) - A353149(n).
EXAMPLE
For n = 15 the 15th row of the triangle A196020 is [29, 13, 7, 0, 1]. The sum of the even-indexed terms is 13 + 0 = 13, so a(15) = 13.
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 27 2022
STATUS
approved