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A072037
Palindromic powers (with positive exponents) of a prime but not a prime (A025475).
3
4, 8, 9, 121, 343, 1331, 10201, 14641, 94249, 1030301, 104060401, 900075181570009, 10022212521222001, 12124434743442121, 12323244744232321, 12341234943214321, 1022321210249420121232201, 1210024420147410244200121, 1210222232227222322220121
OFFSET
1,1
EXAMPLE
E.g. 94249=307*307
MATHEMATICA
a = {}; Do[pp = Prime[n]^i; d = IntegerDigits[pp]; If[d == Reverse[d], a = Append[a, pp]], {n, 1, PrimePi[ Sqrt[10^21]]}, {i, 2, Floor[ Log[ Prime[n], 10^21]]}]; Sort[a] (Robert G. Wilson v)
PROG
(PARI) {a=10^15; v=[]; m=sqrt(a); forprime(p=2, m, q=p; while((q=q*p)<a, n=q; rev=0; while(n>0, d=divrem(n, 10); n=d[1]; rev=10*rev+d[2]); if(q==rev, v=concat(v, q)))); v=vecsort(v); for(j=1, matsize(v)[2], print1(v[j], ", "))}
CROSSREFS
Sequence in context: A046450 A077271 A084093 * A076703 A360900 A305372
KEYWORD
base,easy,nonn
AUTHOR
Labos Elemer, Jun 07 2002
EXTENSIONS
Two more term from Klaus Brockhaus, Jun 07 2002
Four more terms from Robert G. Wilson v, Oct 31 2002
Added a(17)-a(19), clarified definition, Donovan Johnson, Sep 01 2012
STATUS
approved