login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A074165 Numbers n such that n!!! is an interprime. 1
4, 6, 13, 15, 16, 23, 28, 46, 126, 148, 285 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..11.

MATHEMATICA

PrevPrim[n_] := Block[{k = n - 1}, While[ ! PrimeQ[k], k-- ]; k]; NextPrim[n_] := Block[{k = n + 1}, While[ ! PrimeQ[k], k++ ]; k]; NFactorialM[n_, m_] := Block[{k = n, p = n}, While[k > m, k -= m; p = p*k]; p]; Do[ a = NFactorialM[n, 3]; If[2a == PrevPrim[a] + NextPrim[a], Print[n]], {n, 3, 500}]

CROSSREFS

Cf. A053709 & A074176.

Sequence in context: A168015 A225939 A191199 * A137821 A010061 A063186

Adjacent sequences:  A074162 A074163 A074164 * A074166 A074167 A074168

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 16 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified May 25 03:00 EDT 2013. Contains 225634 sequences.