A100688 - OEIS

A100688

a(n) = prime(n) * 3^prime(n) - 1.

17, 80, 1214, 15308, 1948616, 20726198, 2195382770, 22082967872, 2165293113020, 1990280943581606, 19147875284802356, 16660504517966902430, 1495392851464002242522, 14115049597965094337960, 1249674274871002654525988, 1027312020387041054530226318

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

a(1) = 2*3^2 - 1 = 17.

MATHEMATICA

Do[Print[Prime[n]*3^(Prime[n]) - 1], {n, 1, 20}] (* Stefan Steinerberger, Feb 15 2006 *)

# 3^#-1&/@Prime[Range[20]] (* Harvey P. Dale, Jan 24 2012 *)

PROG

(Magma) [NthPrime(n)*3^NthPrime(n) - 1: n in [1..20]]; // Vincenzo Librandi, Aug 27 2015

CROSSREFS

Cf. A060352.

Sequence in context: A338549 A060934 A228602 * A044204 A044585 A373523

Adjacent sequences: A100685 A100686 A100687 * A100689 A100690 A100691

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Dec 07 2004

EXTENSIONS

More terms from Stefan Steinerberger, Feb 15 2006

a(15)-a(16) from Vincenzo Librandi, Aug 27 2015

STATUS

approved