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.

A153139 Numbers n with property that n^2 is a concatenation of three 3-digit primes.

Original entry on oeis.org

10171, 10371, 10447, 10449, 10451, 11303, 11801, 11827, 12319, 12553, 13387, 13829, 13847, 13903, 13913, 14141, 14549, 15087, 15097, 15153, 15847, 16431, 16841, 16847, 17549, 18363, 18379, 18637, 18697, 18701, 19319, 19337, 19579
Offset: 1

Views

Author

Zak Seidov, Dec 19 2008

Keywords

Comments

There are exactly 60 such numbers.

Examples

			a(1)= 10171, 10171^2=103_449_241
a(2)= 10371, 10371^2=107_557_641
a(60)=31591, 31591^2=997_991_281
		

Crossrefs

Programs

  • Mathematica
    ttdpQ[n_]:=Module[{c=FromDigits/@Partition[IntegerDigits[n^2],3]}, Min[ IntegerLength[ c]] ==3&&AllTrue[c,PrimeQ]]; Select[Range[ 10000,31622], ttdpQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 26 2016 *)

A153164 Primes p with property that p^2 is a concatenation of two 3-digit primes.

Original entry on oeis.org

337, 409, 701, 827
Offset: 1

Views

Author

Zak Seidov, Dec 20 2008

Keywords

Comments

There are exactly 4 such numbers.

Examples

			{337,409,701,827}^2 ={113_569, 167_281, 491_401, 683_929}.
		

Crossrefs

Extensions

Edited by Charles R Greathouse IV, Apr 24 2010
Showing 1-2 of 2 results.