Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A090934
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A090934 Primes such that least significant digit swapped with all other digits yields primes. +0
2
2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, 97, 113, 131, 179, 199, 311, 313, 337, 373, 733, 919, 991, 1171, 1399, 1913, 3191, 3313, 3797, 3911, 9733, 11131, 11171, 11311, 13313, 13933, 19979, 31193, 31333, 31379, 31391, 33119, 71191, 71333, 77377 (list; graph; listen)
OFFSET

1,1

COMMENT

Only digits 1,3,7 and 9 can be used for terms with more than 1 digit.

EXAMPLE

179 is a term as 179, 197 & 971 are all prime.

MATHEMATICA

fQ[n_] := Block[{a = c = IntegerDigits[n], b = {}, l = Floor[ Log[10, n] + 1]}, Do[ a = c; {a[[ -1]], a[[i]]} = {a[[i]], a [[ -1]]}; AppendTo[b, FromDigits[a]], {i, 1, l}]; Union[ PrimeQ[b]] == {True}]; Select[Prime[ Range[10000]], fQ[ # ] &] (from Ed Pegg Jr. (ed(AT)mathpuzzle.com), Jan 15 2004)

CROSSREFS

Sequence in context: A007500 A090933 A107845 this_sequence A068652 A003459 A118725

Adjacent sequences: A090931 A090932 A090933 this_sequence A090935 A090936 A090937

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 29 2003

EXTENSIONS

Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 15 2004

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 13 23:45 EST 2009. Contains 170824 sequences.


AT&T Labs Research