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!)
A239211 Squares that are not divisible by any of their nonzero digits. 4
49, 289, 529, 676, 2209, 2809, 4489, 5329, 5776, 5929, 6889, 7396, 8836, 9409, 20449, 24649, 26569, 27889, 29929, 30976, 34969, 37249, 37636, 38809, 49729, 54289, 55696, 59536, 64009, 65536, 66049, 67600, 75076, 76729, 80089, 82369, 85849, 94249, 97969 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A000290 and A038772.

The sequence is infinite since it contains all the terms (5*10^k+3)^2, k>0. - Giovanni Resta, Mar 12 2014

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

EXAMPLE

2809 is in the sequence because 2809 is not divisible by 2, 8 or 9.

MATHEMATICA

Select[Range[350]^2, NoneTrue[#/(IntegerDigits[#]/.(0->Nothing)), IntegerQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 08 2017 *)

PROG

(PARI) isOK(n) = my(v=vecsort(digits(n^2), , 8)); for(i=1+(v[1]==0), #v, if(n^2%v[i]==0, return(0))); 1

s=[]; for(n=1, 1000, if(isOK(n), s=concat(s, n^2))); s

CROSSREFS

Cf. A239210, A239212, A239213.

Cf. A000290, A038772.

Sequence in context: A158248 A219030 A167719 * A198437 A144407 A089552

Adjacent sequences:  A239208 A239209 A239210 * A239212 A239213 A239214

KEYWORD

nonn,base

AUTHOR

Colin Barker, Mar 12 2014

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 22 21:29 EDT 2021. Contains 345393 sequences. (Running on oeis4.)