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A117172 Column 2 of triangle A117170 of Inverse-Shift-Moebius coefficients and so equals the Inverse-Shift-Moebius transform of [0,1,0,0,...]. 4
0, 1, 0, 1, 1, 2, 1, 3, 1, 4, 2, 4, 2, 6, 3, 6, 4, 7, 3, 10, 5, 9, 6, 10, 7, 13, 7, 12, 9, 16, 8, 17, 10, 17, 14, 18, 12, 20, 13, 24, 16, 26, 15, 27, 20, 25, 19, 30, 18, 34, 23, 33, 26, 37, 28, 41, 26, 36, 28, 45, 30, 48, 35, 47, 38, 50, 33, 55, 42, 59, 41, 60, 39, 61, 51, 61, 53, 69 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..78.

PROG

(PARI) {a(n)=if(n<2, 0, prod(i=0, n, matrix(n, n, r, c, if(r>=c, if((r+i)%(c+i)==0, 1, 0))))[n, 2])}

CROSSREFS

Cf. A117170 (triangle), A117171 (column 1), A117173 (column 3), A117174 (row sums).

Sequence in context: A200780 A194943 A087145 * A029207 A111902 A316211

Adjacent sequences:  A117169 A117170 A117171 * A117173 A117174 A117175

KEYWORD

nonn

AUTHOR

Wouter Meeussen and Paul D. Hanna, Mar 05 2006

STATUS

approved

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Last modified July 4 09:40 EDT 2020. Contains 335446 sequences. (Running on oeis4.)