A270231 Smaller member of a twin prime pair with a perfect power sum.

3, 17, 71, 107, 881, 1151, 2591, 3527, 4049, 15137, 20807, 34847, 46817, 69191, 83231, 103967, 112337, 139967, 149057, 176417, 179999, 206081, 281249, 362951, 388961, 438047, 472391, 478241, 538721, 649799, 734471, 808991, 960497, 1080449, 1143071, 1152161, 1254527

Offset: 1

Author

Altug Alkan, Mar 13 2016

Keywords

• nonn

Comments

A069496 is a subsequence.

Examples

			3 is a term because 3 + 5 = 2^3.
17 is a term because 17 + 19 = 6^2.
107 is a term because 107 + 109 = 6^3.
139967 is a term because 139967 + 139969 = 6^7.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A001359, A069496, A330978, A330980.

First bisection of A119768.

Programs

Magma

[p:p in PrimesUpTo(1300000)|IsPrime(p+2) and IsPower(2*p+2)]; // Marius A. Burtea, Dec 20 2019

PARI

t(n,p=3) = { while( p+2 < (p=nextprime( p+1 )) || n-->0, ); p-2}
for(n=1, 1e4, if(ispower(2*t(n)+2), print1(t(n), ", ")));