A225389 Prime powers (A025475) representable as (p+q)/2, where p and q are distinct prime powers, in two or more ways.

781370209, 59015782001929, 109012413691801, 185341023228001, 275502533796361, 315952509152809, 613721000732449, 1579642847367841, 3182047597748881, 5927491050020401, 13602074755852489, 22706626517726761

Offset

1,1

Comments

Prime powers p such that there are x and y such that p+x, p-x, p+y, p-y are four distinct prime powers.

First 12 terms are squares of prime numbers.

Conjecture: the sequence is infinite.

Links

Table of n, a(n) for n=1..12.

Crossrefs

Cf. A025475, A225388.

Sequence in context: A297867 A344729 A344730 * A166121 A348079 A046186

Adjacent sequences: A225386 A225387 A225388 * A225390 A225391 A225392

Keyword

nonn,hard,more

Author

Alex Ratushnyak, May 05 2013

Status

approved