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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A033274 Primes that do not contain any other prime as a substring. 25
2, 3, 5, 7, 11, 19, 41, 61, 89, 101, 109, 149, 181, 401, 409, 449, 491, 499, 601, 691, 809, 881, 991, 1009, 1049, 1069, 1481, 1609, 1669, 1699, 1801, 4001, 4049, 4481, 4649, 4801, 4909, 4969, 6091, 6469, 6481, 6869, 6949, 8009, 8069, 8081, 8609, 8669, 8681 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If there is more than one digit, all digits must be nonprime numbers.

A179335(n) = prime(n) iff prime(n) is in this sequence. For n > 4, prime(n) is in this sequence iff A109066(n) = 0. - Reinhard Zumkeller, Jul 11 2010, corrected by M. F. Hasler, Aug 27 2012

A079066(n) = 0 iff prime(n) is in this sequence. [Corrected by M. F. Hasler, Aug 27 2012]

What are the asymptotics of this sequence? - Charles R Greathouse IV, Aug 27 2012

LINKS

Zak Seidov, Table of n, a(n) for n = 1..1000.

EXAMPLE

149 is a term as 1,4,9,14,49 are all nonprimes. 199 is not a member as 19 is a prime.

MATHEMATICA

f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 1100, f@# == 1 &] (* Robert G. Wilson v, Aug 01 2010 *)

PROG

(Haskell)

import Data.List (elemIndices)

a033274 n = a033274_list !! (n-1)

a033274_list = map (a000040 . (+ 1)) $ elemIndices 0 a079066_list

-- Reinhard Zumkeller, Jul 19 2011

CROSSREFS

Cf. A089768, A089770, A039996, A079397, A033274, A034844, A179909-A179919.

Sequence in context: A118985 A092728 A089769 * A071062 A002231 A087769

Adjacent sequences:  A033271 A033272 A033273 * A033275 A033276 A033277

KEYWORD

base,nonn

AUTHOR

Michael Kleber

EXTENSIONS

Edited by N. J. A. Sloane at the suggestion of Luca Colucci, Apr 03 2008

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 18 12:21 EST 2017. Contains 294891 sequences.