A084885 - OEIS

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A084885

Triangular array, read by rows: T(n,k) = denominator of arithmetic derivative of n/k, 1<=k<=n.

1, 1, 1, 1, 4, 1, 1, 1, 9, 1, 1, 4, 9, 1, 1, 1, 1, 1, 4, 25, 1, 1, 4, 9, 2, 25, 36, 1, 1, 1, 9, 1, 25, 9, 49, 1, 1, 4, 1, 4, 25, 4, 49, 16, 1, 1, 1, 9, 4, 1, 9, 49, 1, 27, 1, 1, 4, 9, 2, 25, 36, 49, 16, 27, 100, 1, 1, 1, 1, 1, 25, 1, 49, 4, 9, 25, 121, 1

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,5

COMMENTS

Arithmetic derivative of n/k = (k*A003415(n)-n*A003415(k))/k^2;

LINKS

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

Eric Weisstein's World of Mathematics, Quotient Rule.

EXAMPLE

......................... 0

................... 1 ........ 0

............... 1 .... -1/4 ....... 0