OFFSET
1,1
EXAMPLE
4 = 8 - 4 = 125 -121, 7 = 16 - 9 = 32768 - 32761, 17 = 49 - 32 = 81 -64 = 529 - 512, etc.
MATHEMATICA
pp = Sort[ Flatten[ Table[ Prime[n]^i, {n, 1, PrimePi[ Sqrt[10^16]]}, {i, 1, Log[ Prime[n], 10^16]]]}]]]; l = Length[pp]; b = Sort[ Take[pp, -l + 1] - Take[pp, l - 1]]; Union[ b[[ Select[ Range[375], b[[ # ]] == b[[ # + 1]] &]]]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Oct 31 2002
STATUS
approved