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 A086712 Number of times the n-th prime power can be written as an arithmetic mean of two other prime powers. 0
 0, 1, 2, 2, 3, 3, 3, 4, 3, 4, 6, 6, 5, 5, 7, 8, 5, 6, 6, 7, 6, 8, 6, 8, 8, 7, 8, 10, 10, 9, 8, 9, 14, 8, 10, 11, 10, 12, 8, 11, 8, 12, 13, 12, 11, 11, 13, 13, 13, 13, 13, 11, 11, 14, 11, 13, 16, 12, 16, 14, 15, 16, 17, 13, 16, 15, 12, 18, 27, 15, 19, 18, 17, 15, 16, 15, 13, 18, 17, 15 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Eric Weisstein's World of Mathematics, Prime Power EXAMPLE n=7, A000961(7)=8=2^3: (3+13)/2=(A000961(3)+A000961(10))/2, (5+11)/2=(A000961(5)+A000961(9))/2 and (7+3^2)/2=(A000961(6)+A000961(8))/2: therefore a(7)=3. CROSSREFS Cf. A000961, A071681. Sequence in context: A000121 A230022 A049846 * A125842 A029865 A211190 Adjacent sequences:  A086709 A086710 A086711 * A086713 A086714 A086715 KEYWORD nonn AUTHOR Reinhard Zumkeller, Aug 01 2003 STATUS approved

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Last modified April 16 03:56 EDT 2021. Contains 343030 sequences. (Running on oeis4.)