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

1,1

Comments

A069496 is a subsequence.

Links

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

Example

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.

Prog

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

Crossrefs

Cf. A001359, A069496, A330978, A330980.

First bisection of A119768.

Sequence in context: A357923 A069468 A241776 * A265919 A317452 A128948

Adjacent sequences: A270228 A270229 A270230 * A270232 A270233 A270234

Keyword

nonn

Author

Altug Alkan, Mar 13 2016

Status

approved