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A117171 Column 1 of triangle A117170 of Inverse-Shift-Moebius coefficients and so equals the Inverse-Shift-Moebius transform of [1,0,0,0,...]. 4
1, 1, 2, 2, 3, 3, 4, 3, 6, 5, 5, 6, 7, 7, 10, 7, 8, 10, 11, 11, 14, 11, 11, 14, 16, 14, 18, 17, 17, 21, 18, 17, 23, 22, 24, 25, 21, 24, 32, 28, 27, 33, 28, 32, 39, 30, 31, 36, 38, 41, 42, 41, 38, 50, 48, 44, 48, 45, 46, 59, 49, 53, 65, 55, 59, 63, 56, 65, 71, 70, 61, 72, 62, 72, 84 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..75.

PROG

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

CROSSREFS

Cf. A117170 (triangle), A117172 (column 2), A117173 (column 3), A117174 (row sums).

Sequence in context: A242767 A027833 A110676 * A325356 A304706 A084054

Adjacent sequences:  A117168 A117169 A117170 * A117172 A117173 A117174

KEYWORD

nonn

AUTHOR

Wouter Meeussen and Paul D. Hanna, Mar 05 2006

STATUS

approved

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Last modified August 7 23:56 EDT 2020. Contains 336280 sequences. (Running on oeis4.)