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

1,2

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..6228

Example

9801=3^4*11^2 and 1089=3^2*11^2.

Prog

(PARI) is(n)=ispowerful(n) && ispowerful(subst(Polrev(digits(n)), 'x, 10)) \\ Charles R Greathouse IV, Sep 16 2014
(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

Crossrefs

Cf. A001694, A115655, A085751.

Sequence in context: A115697 A075783 A098121 * A076705 A306916 A355063

Adjacent sequences: A115653 A115654 A115655 * A115657 A115658 A115659

Keyword

base,nonn

Author

Giovanni Resta, Jan 28 2006

Status

approved