A091625 Number of consecutive primes less than 10^n such that their sum is a perfect power (A091624).

1, 5, 8, 17, 34, 87, 203, 510, 1331

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; PrimeExponents[n_] := Flatten[ Table[ #[[2]], {1}] & /@ FactorInteger[n]]; c = 0; p = q = 2; Do[ While[p < 10^n, q = NextPrim[p]; If[ Apply[ GCD, PrimeExponents[p + q]] > 1, c++ ]; p = q]; Print[c], {n, 1, 8}]

Crossrefs

Cf. A001597, A091624.

Sequence in context: A031191 A365591 A212115 * A027601 A261808 A057592

Adjacent sequences: A091622 A091623 A091624 * A091626 A091627 A091628

Keyword

nonn

Author

Robert G. Wilson v, Jan 24 2004

Status

approved