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A057820
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First differences of sequence of consecutive prime powers (A000961).
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20
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1, 1, 1, 1, 2, 1, 1, 2, 2, 3, 1, 2, 4, 2, 2, 2, 2, 1, 5, 4, 2, 4, 2, 4, 6, 2, 3, 3, 4, 2, 6, 2, 2, 6, 8, 4, 2, 4, 2, 4, 8, 4, 2, 1, 3, 6, 2, 10, 2, 6, 6, 4, 2, 4, 6, 2, 10, 2, 4, 2, 12, 12, 4, 2, 4, 6, 2, 2, 8, 5, 1, 6, 6, 2, 6, 4, 2, 6, 4, 14, 4, 2, 4, 14, 6, 6, 4, 2, 4, 6, 2, 6, 6, 6, 4, 6, 8, 4, 8, 10, 2, 10
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OFFSET
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1,5
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COMMENTS
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LINKS
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FORMULA
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EXAMPLE
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Odd differences arise in pairs in neighborhoods of powers of 2, like {..,2039,2048,2053,..} gives {..,11,5,..}
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MAPLE
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MATHEMATICA
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Map[Length, Split[Table[Apply[LCM, Range[n]], {n, 1, 150}]]] (* Geoffrey Critzer, May 29 2015 *)
Join[{1}, Differences[Select[Range[500], PrimePowerQ]]] (* Harvey P. Dale, Apr 21 2022 *)
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PROG
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(PARI) isA000961(n) = (omega(n) == 1 || n == 1)
n_prev=1; for(n=2, 500, if(isA000961(n), print(n-n_prev); n_prev=n)) \\ Michael B. Porter, Oct 30 2009
(Haskell)
a057820_list = zipWith (-) (tail a000961_list) a000961_list
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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