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A074936 Number of perfect powers between two successive nonprime prime powers. 0
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 3, 0, 0, 1, 0, 3, 0, 1, 1, 1, 1, 1, 4, 0, 3, 2, 2, 1, 0, 0, 1, 4, 2, 4, 1, 2, 2, 3, 0, 1, 6, 1, 1, 0, 6, 2, 7, 3, 1, 4, 1, 1, 2, 8, 3, 1, 0, 1, 1, 6, 1, 1, 9, 1, 5, 0, 5, 4, 1, 3, 0, 5, 1, 0, 10, 1, 3, 2, 12, 11, 2, 1, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,15

LINKS

Table of n, a(n) for n=1..88.

Eric Weisstein's World of Mathematics, Perfect Power.

Eric Weisstein's World of Mathematics, Prime Power.

EXAMPLE

There are three perfect powers with composite roots between A025475(15)=169=13^2 and A025475(15+1)=243=3^5: 196=(2*7)^2, 216=3^5 and 225=(3*5)^2; therefore a(15)=3.

a(16)=0, since there are no perfect powers between A025475(16)=243=3^5 and A025475(16+1)=256=2^8.

CROSSREFS

Cf. A001597, A025475.

Sequence in context: A324862 A324864 A171913 * A035655 A239446 A036857

Adjacent sequences:  A074933 A074934 A074935 * A074937 A074938 A074939

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 10 2002

STATUS

approved

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Last modified November 18 12:16 EST 2019. Contains 329261 sequences. (Running on oeis4.)