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!)
A157711 Primes made up of 0's and four 1's only. 3
10111, 1011001, 1100101, 10010101, 10100011, 101001001, 1000001011, 1000010101, 1010000011, 1100010001, 10000001101, 10001000011, 10001001001, 10001100001, 10100000011, 10100001001, 11000000101, 11001000001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A062339 and A020449. Subsequence of A235154. - Felix Fröhlich, Nov 19 2014

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

MAPLE

for d from 4 to 18 do for c from 0 to 2^d-1 do bdgs := convert(c, base, 2) ; if add(i, i=bdgs) = 3 then p := 10^d+add(op(i, bdgs)*10^(i-1), i=1..nops(bdgs)) ; if isprime(p) then printf("%d, ", p) ; fi; fi; od: od: # R. J. Mathar, Mar 06 2009

MATHEMATICA

Flatten[Select[FromDigits/@Permutations[Join[{1, 1, 1, 1}, PadRight[{}, 7, 0]]], PrimeQ]] // Union (* Harvey P. Dale, May 09 2019 *)

PROG

(PARI) for(n=0, 10, forprime(p=10^n, (10^(n+1)-1)/9, if(vecmax(digits(p))==1, if(sumdigits(p)==4, print1(p, ", "))))) \\ Felix Fröhlich, Nov 19 2014

CROSSREFS

Sequence in context: A191244 A269066 A161786 * A159863 A234180 A054037

Adjacent sequences:  A157708 A157709 A157710 * A157712 A157713 A157714

KEYWORD

nonn,base

AUTHOR

Lekraj Beedassy, Mar 04 2009

EXTENSIONS

Extended by numerous authors, Mar 06 2009

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 June 1 17:57 EDT 2020. Contains 334762 sequences. (Running on oeis4.)