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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS 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)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 Cf. A025475, A002385. Sequence in context: A046450 A077271 A084093 * A076703 A305372 A261602 Adjacent sequences:  A072034 A072035 A072036 * A072038 A072039 A072040 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

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Last modified December 12 01:57 EST 2019. Contains 329948 sequences. (Running on oeis4.)