A028866 - OEIS

%I #15 Feb 13 2020 01:16:46

%S 4,9,25,49,169,289,1369,4489,6889,11449,27889,113569,134689,146689,

%T 344569,2778889,27777888889,111113555569,111133556689,111333666889,

%U 113344668889,444444888889,1111133355666889,1133444466888889

%N Squares of primes having digits in nondecreasing order.

%C What is the rate of growth of this sequence?

%t Select[Prime[Range[100]]^2, IntegerDigits[#] == Sort[IntegerDigits[#]] &] (* _Alonso del Arte_, Jan 18 2017 *)

%o (PARI) is(n)=my(d=digits(n));d==vecsort(d) && issquare(n,&n) && isprime(n) \\ _Charles R Greathouse IV_, Jun 05 2013

%Y Subsequence of A052043.

%Y Cf. A028865, A028868, A028869.

%K nonn,base,less

%O 1,1

%A _Patrick De Geest_

%E Title changed to reflect terms by _Sean A. Irvine_, Feb 12 2020