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A104025 Least number k that can be written as k^2 * j with 0 < j <= k and gcd(k, j) = 1 in n ways. 1
2, 1, 100, 900, 44100, 108900, 1232100, 11492100, 5336100, 12744900, 97416900 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..10.

MATHEMATICA

t = Sort[ Flatten[ Table[n = k^2*j; If[ GCD[k, j] == 1 && 10^5 < n < 10^8, n, {}], {k, 15000}, {j, k}]]]; l = Length[t]; t[[Select[ Range[l - 11], t[[ # ]] == t[[ # + 9]] &]]]

CROSSREFS

Cf. A102354, A104021, A104023.

Sequence in context: A141527 A301631 A191298 * A335600 A039923 A081708

Adjacent sequences:  A104022 A104023 A104024 * A104026 A104027 A104028

KEYWORD

nonn

AUTHOR

Leroy Quet and Robert G. Wilson v, Feb 23 2005

STATUS

approved

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Last modified July 24 20:26 EDT 2021. Contains 346273 sequences. (Running on oeis4.)