A028866 Squares of primes having digits in nondecreasing order.

4, 9, 25, 49, 169, 289, 1369, 4489, 6889, 11449, 27889, 113569, 134689, 146689, 344569, 2778889, 27777888889, 111113555569, 111133556689, 111333666889, 113344668889, 444444888889, 1111133355666889, 1133444466888889

Offset

1,1

Comments

What is the rate of growth of this sequence?

Links

Table of n, a(n) for n=1..24.

Mathematica

Select[Prime[Range[100]]^2, IntegerDigits[#] == Sort[IntegerDigits[#]] &] (* Alonso del Arte, Jan 18 2017 *)

Prog

(PARI) is(n)=my(d=digits(n)); d==vecsort(d) && issquare(n, &n) && isprime(n) \\ Charles R Greathouse IV, Jun 05 2013

Crossrefs

Subsequence of A052043.

Cf. A028865, A028868, A028869.

Sequence in context: A133019 A376746 A326708 * A146981 A068373 A030481

Adjacent sequences: A028863 A028864 A028865 * A028867 A028868 A028869

Keyword

nonn,base,less

Author

Patrick De Geest

Extensions

Title changed to reflect terms by Sean A. Irvine, Feb 12 2020

Status

approved