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.

Showing 1-2 of 2 results.

A080178 Non-palindromic primes which on subtracting their reversal gives perfect cubes.

Original entry on oeis.org

41, 2141, 2251, 3251, 3361, 3581, 3691, 4253, 4363, 4583, 5693, 8147, 9257, 9587, 9697, 46301, 46601, 46901, 47111, 47711, 47911, 48121, 48221, 48821, 49031, 49331, 49531, 49831, 66103, 66403, 67213, 68023, 69233, 69833, 400051, 409951, 414461
Offset: 1

Views

Author

Shyam Sunder Gupta, Mar 16 2003

Keywords

Examples

			a(1) = 41 because 41-14 = 27 which is a perfect cube.
		

Crossrefs

Programs

  • Mathematica
    okQ[n_]:=Module[{idn=IntegerDigits[n],ridn},ridn=Reverse[idn];idn!=ridn&&IntegerQ[Power[n-FromDigits[ridn], (3)^-1]]]
    Select[Prime[Range[35000]],okQ]  (* Harvey P. Dale, Mar 08 2011 *)

A232183 Primes p such that p-R(p) is a square, where R = reversal of digits = A004086.

Original entry on oeis.org

2, 3, 5, 7, 11, 43, 73, 101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 2141, 2251, 4253, 4363, 4583, 6701, 7211, 7321, 7541, 8147, 8923, 9103, 9323, 9433, 10301, 10501, 10601, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14341, 14741
Offset: 1

Views

Author

M. F. Hasler, Nov 20 2013

Keywords

Comments

This sequence includes the palindromic primes for which p-R(p)=0. See A080177 = (43,73,2141,2251,4253,4363,...) for the variant not including palindromes.

Programs

  • PARI
    forprime(p=1,19999,issquare(p-A004086(p))&&print1(p","))
Showing 1-2 of 2 results.