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A156837
Triangle read by rows, A051731 * A156348
2
1, 2, 1, 2, 0, 1, 3, 3, 0, 1, 2, 0, 0, 0, 1, 4, 4, 4, 0, 0, 1, 2, 0, 0, 0, 0, 0, 1, 4, 7, 0, 5, 0, 0, 0, 1, 3, 0, 7, 0, 0, 0, 0, 0, 1, 4, 6, 0, 0, 6, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 12, 14, 11, 0, 7, 0, 0, 0, 0, 0, 1
OFFSET
1,2
COMMENTS
Left border: A000005(n).
Row sums = 3 iff n-th row is prime.
FORMULA
Triangle read by rows, A051731 * A156348 = inverse Mobius transform of A156348
EXAMPLE
First few rows of the triangle =
1;
2, 1;
2, 0, 1;
3, 3, 0, 1;
2, 0, 0, 0, 1;
4, 4, 4, 0, 0, 1;
2, 0, 0, 0, 0, 0, 1;
4, 7, 0, 5, 0, 0, 0, 1;
3, 0, 7, 0, 0, 0, 0, 0, 1;
4, 6, 0, 0, 6, 0, 0, 0, 0, 1;
2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
6, 12, 14, 11, 0, 7, 0, 0, 0, 0, 0, 1;
2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
4, 8, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 1;
...
MAPLE
A156837 := proc(n, k)
add(A051731(n, j)*A156348(j, k), j=k..n) ;
end proc: # R. J. Mathar, Mar 03 2013
CROSSREFS
Cf. A156348, A051731, A000005, A156838 (row sums).
Sequence in context: A127170 A143335 A099505 * A255935 A374394 A129559
KEYWORD
nonn,tabl,easy
AUTHOR
STATUS
approved