cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

User: Rabii Younès

Rabii Younès's wiki page.

Rabii Younès has authored 1 sequences.

A253912 Fourth powers whose reversal is a prime.

Original entry on oeis.org

16, 38416, 130321, 160000, 923521, 1500625, 13845841, 14776336, 16777216, 38950081, 163047361, 181063936, 312900721, 322417936, 384160000, 937890625, 1303210000, 1600000000, 3722098081, 7992538801, 9235210000, 13841287201, 15006250000, 16610312161, 17748900625, 31414372081, 37141383841
Offset: 1

Author

Rabii Younès, Jan 18 2015

Keywords

Comments

Intersection of A000583 and A095179.
As the last digits of primes are not even or 5 (except for primes 2 and 5), the terms do not start with an even number or 5. If m is an integer such that the reversal of m^4 is prime and sqrt4(n) is the fourth root of n then m is not of the form [sqrt4(2 * 10^k), sqrt4(3 * 10^k)] or [sqrt4(4 * 10^k), sqrt4(7 * 10^k)] for nonnegative k etc. - David A. Corneth, Jun 02 2016
All terms == 1 mod 3. - Robert Israel, Jun 03 2016

Examples

			Example: a(1) = 16 is a fourth power because 16 = 2^4 and the reverse of 16 is 61 which is a prime number.
		

Crossrefs

Cf. A000583 (fourth power), A095179 (reversal of n is prime).
Cf. A058996 (primes whose reversal is a fourth power).

Programs

  • Mathematica
    Select[Range[440]^4, PrimeQ[FromDigits@ Reverse@ IntegerDigits@ #] &] (* Michael De Vlieger, Jan 19 2015 *)
  • Python
    from sympy import isprime
    A253912_list = [n for n in (i**4 for i in range(10**6)) if isprime(int(str(n)[::-1]))] # Chai Wah Wu, Jun 02 2016