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A333969 Squares of terms are the intersection of A025487 and A217584. 1
1, 12, 60, 1260, 13860, 180180, 277200, 900900, 3628800, 15315300, 28828800, 38880000, 290990700, 373248000, 428828400, 2036934900, 2477260800, 3632428800, 6692786100, 8147739600, 13335840000, 15682867200, 15925248000, 20956320000, 46849502700, 61751289600, 65181916800, 68976230400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

As all terms in A217584 are squares so these list the square roots.

Also: Numbers k such that k^2 is the least positive integer having its prime signature and d(k^4)/d(k^2) is an integer.

LINKS

David A. Corneth, Table of n, a(n) for n = 1..3393

EXAMPLE

12 is in the sequence as 12^2 = 144 and 144^2 has 45 divisors and 144 has 15 divisors and 45/15 = 3 is integer and 12 is in A025487 and so is 144.

CROSSREFS

Cf. A025487, A217584.

Sequence in context: A056388 A056378 A231026 * A076504 A232700 A354882

Adjacent sequences: A333966 A333967 A333968 * A333970 A333971 A333972

KEYWORD

nonn

AUTHOR

David A. Corneth, May 30 2020

STATUS

approved

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Last modified January 30 12:01 EST 2023. Contains 359943 sequences. (Running on oeis4.)