login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A140853 a(n) = prime(prime(n) - 1) - 1, where prime(n) is the n-th prime. 4
1, 2, 6, 12, 28, 36, 52, 60, 78, 106, 112, 150, 172, 180, 198, 238, 270, 280, 316, 348, 358, 396, 420, 456, 502, 540, 556, 576, 592, 612, 700, 732, 768, 786, 856, 862, 910, 952, 982, 1020, 1060, 1068, 1150, 1162, 1192, 1212, 1290, 1398, 1428, 1438, 1458 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A055003(n) - 1. - N. J. A. Sloane, Jul 31 2008

a(n) ~ n (log n)^2. - Charles R Greathouse IV, Apr 07 2015

MATHEMATICA

Table[Prime[Prime[n - 1] - 1] - 1, {n, 2, 60}] (* Vincenzo Librandi, Apr 05 2015 *)

PROG

(PARI) apply(p->prime(p-1)-1, primes(100))

CROSSREFS

Cf. A006093, A055003.

Sequence in context: A166963 A188476 A155583 * A185961 A290674 A290419

Adjacent sequences:  A140850 A140851 A140852 * A140854 A140855 A140856

KEYWORD

nonn,easy

AUTHOR

Juri-Stepan Gerasimov, Jul 30 2008

EXTENSIONS

Corrected (382 replaced by 396) and extended by R. J. Mathar, Apr 27 2010

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 30 07:18 EDT 2021. Contains 346348 sequences. (Running on oeis4.)