A077649 - OEIS

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A077649

Initial digits of composite numbers.

4, 6, 8, 9, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	FORMULA	`a[n]=A000030[A002808(n)]`
	MATHEMATICA	`c[x_] := FixedPoint[x+PrimePi[ # ]+1&, x] Table[First[IntegerDigits[c[w]]], {w, 1, 128}]` `First[IntegerDigits[#]]&/@Complement[Range[150], Prime[Range[ PrimePi[150]]]] (* From Harvey P. Dale, Apr 26 2011 *)`
	CROSSREFS	`Cf. A000030, A002808, A077648.` `Sequence in context: A165957 A110750 A129808 * A132025 A200363 A123870` `Adjacent sequences: A077646 A077647 A077648 * A077650 A077651 A077652`
	KEYWORD	`base,easy,nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Nov 19 2002`

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Last modified February 17 11:46 EST 2012. Contains 206011 sequences.