A077273 Ordered differences without repetitions between two successive powers of a prime but not a prime (A025475).

1, 2, 3, 4, 5, 7, 9, 10, 12, 13, 15, 17, 18, 30, 33, 38, 40, 41, 54, 63, 74, 94, 96, 104, 112, 120, 128, 138, 139, 151, 168, 186, 192, 199, 240, 248, 250, 255, 260, 271, 286, 288, 298, 307, 312, 316, 320, 354, 356, 362, 375, 393, 408, 423, 424, 432, 496, 504, 513

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Example

33 = 546 - 513 = 2568 - 2535 = 6168 - 6135 = 458703 - 458670 = 885465 - 885432 = 1048608 - 1048575 = 6291480 - 6291447 = 37748688 - 37748655 = 125829345 - 125829312.

Mathematica

pp = Sort[ Flatten[ Table[ Prime[n]^i, {n, 1, PrimePi[ Sqrt[10^16]]}, {i, 1, Log[ Prime[n], 10^16]}]]]; l = Length[pp]; d = Sort[Take[pp, -l + 1] - Take[pp, l - 1]]; Union[ Take[d, 10^5]]

Crossrefs

Cf. A025475.

Sequence in context: A123538 A092999 A077154 * A032955 A320848 A228234

Adjacent sequences: A077270 A077271 A077272 * A077274 A077275 A077276

Keyword

nonn

Author

Robert G. Wilson v, Oct 31 2002

Status

approved