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A036380 Number of true prime powers whose binary order, ceiling(log_2(p^x)), is n. 2
0, 1, 1, 2, 3, 2, 4, 3, 4, 6, 5, 9, 10, 11, 17, 15, 26, 31, 39, 53, 68, 90, 125, 159, 216, 290, 391, 536, 719, 971, 1329, 1812, 2477, 3386, 4626, 6351, 8729, 11995, 16459, 22669, 31259, 43049 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

The 5 prime powers between 1025 and 2048 (inclusive) are 1331 = 11^3, 1369 = 37^2, 1681 = 41^2, 1849 = 43^2, and 2048 = 2^11.

MATHEMATICA

t=Table[Length[Union[Flatten[Table[Table[Prime[w]^s, {w, 1, PrimePi[2^(n/s)]}], {s, 2, g+1}]]] ], {n, 1, 42}] Delete[t-RotateRight[t], 1]

CROSSREFS

Cf. A029837, A036378-A036390.

Sequence in context: A076753 A245134 A068962 * A241054 A257907 A139094

Adjacent sequences:  A036377 A036378 A036379 * A036381 A036382 A036383

KEYWORD

nonn

AUTHOR

Labos Elemer

STATUS

approved

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Last modified June 20 09:27 EDT 2019. Contains 324234 sequences. (Running on oeis4.)