A115656 Both n and the reverse of n are powerful(1) numbers (A001694).
1, 4, 8, 9, 27, 72, 100, 121, 144, 169, 343, 400, 441, 484, 576, 675, 676, 800, 900, 961, 1000, 1089, 1331, 1800, 2700, 3087, 4000, 7200, 7803, 8000, 9000, 9801, 10000, 10201, 10404, 10609, 12100, 12321, 12544, 12769, 14400, 14641, 14884
Offset: 1
Examples
9801=3^4*11^2 and 1089=3^2*11^2.
Links
- Charles R Greathouse IV, Table of n, a(n) for n = 1..6228
Programs
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PARI
is(n)=ispowerful(n) && ispowerful(subst(Polrev(digits(n)),'x,10)) \\ Charles R Greathouse IV, Sep 16 2014
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PARI
has(n)=ispowerful(subst(Polrev(digits(n)),'x,10)) list(lim)=my(v=List(),t,t2); for(m=1,lim^(1/3), t=m^3; for(n=1,sqrtint(lim\t), if(has(t2=t*n^2), listput(v,t2)))); Set(v) \\ Charles R Greathouse IV, Sep 16 2014