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A228593 a(1) = 2, a(n) = a(n-1)*prime(n-1)*prime(n), where prime(n) denotes the n-th prime number. 1
2, 12, 180, 6300, 485100, 69369300, 15330615300, 4951788741900, 2163931680210300, 1443342430700270100, 1297564845199542819900, 1488306877443875614425300, 2257761533082359307083180100, 3980433582824199458387646516300 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No sum of any number of terms is a perfect power.

LINKS

Table of n, a(n) for n=1..14.

Wikipedia, Perfect power

FORMULA

a(1) = 2; a(n) = 2*(product_{i=1..n-1} A006094(i)), n >= 2.

MATHEMATICA

nxt[{n_, a_}]:={n+1, a Prime[n]Prime[n+1]}; NestList[nxt, {1, 2}, 20][[All, 2]] (* Harvey P. Dale, Feb 19 2020 *)

PROG

(MAGMA) [n le 1 select 2 else Self(n-1)*NthPrime(n-1)*NthPrime(n): n in [1..14]]

CROSSREFS

Cf. A000040, A001597, A006094.

Sequence in context: A125861 A228508 A156516 * A067962 A134716 A243807

Adjacent sequences:  A228590 A228591 A228592 * A228594 A228595 A228596

KEYWORD

easy,nonn,changed

AUTHOR

Arkadiusz Wesolowski, Aug 27 2013

STATUS

approved

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Last modified February 22 12:00 EST 2020. Contains 332135 sequences. (Running on oeis4.)