id:A087874 - OEIS Search Results

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a[n] =PrimePi[PrimePi[n-1]] + a[n - a[n-1]]

+0
1

1, 1, 1, 2, 2, 4, 3, 4, 4, 6, 4, 7, 7, 6, 7, 7, 9, 8, 8, 11, 10, 11, 11, 11, 10, 11, 11, 13, 11, 12, 12, 16, 14, 16, 13, 16, 15, 16, 16, 16, 15, 17, 17, 17, 19, 17, 18, 18, 18, 22, 17, 19, 22, 22, 20, 22, 19, 22, 21, 23, 23, 23, 23, 22, 24, 24, 24, 25, 25, 27, 25, 26, 26, 26, 26, 30 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`A reinversion type sequence using the distribution sequence of the primes as the inverse function and A004001 as the pattern function.` `Frequency count shows this sequence doesn't cover the integer domain.`
	MATHEMATICA	`crid[n_Integer?Positive] := crid[n] =PrimePi[PrimePi[n-1]] + crid[n - crid[n-1]] crid[1] = crid[2] = 1 digits=256 a=Table[crid[n], {n, 1, digits}]`
	CROSSREFS	`Cf. A004001.` `Adjacent sequences: A087871 A087872 A087873 this_sequence A087875 A087876 A087877` `Sequence in context: A107331 A087808 A094950 this_sequence A117484 A086835 A046701`
	KEYWORD	`nonn`
	AUTHOR	`Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Oct 11 2003`

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Last modified October 15 09:18 EDT 2008. Contains 145015 sequences.

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