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A100690 a(n) = p * 5^p - 1 where p=prime(n). 1
49, 374, 15624, 546874, 537109374, 15869140624, 12969970703124, 362396240234374, 274181365966796874, 5401670932769775390624, 144354999065399169921874, 2692104317247867584228515624 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..224

FORMULA

a(n) = A064751(prime(n)) = A064751(A000040(n)). - Michel Marcus, Aug 27 2015

EXAMPLE

a(1) = 2*5^2 - 1 = 49.

MATHEMATICA

Do[Print[Prime[n]*5^(Prime[n]) - 1], {n, 1, 20}] (* Stefan Steinerberger, Feb 15 2006 *)

#*5^#-1&/@Prime[Range[20]] (* Harvey P. Dale, Jun 12 2016 *)

PROG

(PARI) main(m)=forprime(p=2, m, print1(p * 5^p - 1, ", ")) \\ Anders Hellström, Aug 27 2015

(MAGMA) [NthPrime(n) * 5^(NthPrime(n)) - 1: n in [1..20]]; // Vincenzo Librandi, Aug 27 2015

CROSSREFS

Sequence in context: A206255 A017606 A206248 * A157882 A168572 A063874

Adjacent sequences:  A100687 A100688 A100689 * A100691 A100692 A100693

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Dec 07 2004

EXTENSIONS

More terms from Stefan Steinerberger, Feb 15 2006

STATUS

approved

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Last modified May 12 13:46 EDT 2021. Contains 343823 sequences. (Running on oeis4.)