A053158 - OEIS

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A053158

Sum of n and its cototient function value (A051953).

1, 3, 4, 6, 6, 10, 8, 12, 12, 16, 12, 20, 14, 22, 22, 24, 18, 30, 20, 32, 30, 34, 24, 40, 30, 40, 36, 44, 30, 52, 32, 48, 46, 52, 46, 60, 38, 58, 54, 64, 42, 72, 44, 68, 66, 70, 48, 80, 56, 80, 70, 80, 54, 90, 70, 88, 78, 88, 60, 104, 62, 94, 90, 96, 82, 112, 68, 104, 94, 116 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`For Mersenne primes and also for certain composites the values of this function are powers of 2.`
	FORMULA	`a(n)=n+A051953(n)=2n-EulerPhi(n)`
	EXAMPLE	`n=127, a(127)=254-126=128 n=80, a(80)=160-32=128 n=2^s, a(2^s)=3*2^(s-1)`
	CROSSREFS	`A000043, A000668, A001368, A051953.` `Sequence in context: A175708 A023830 A063649 * A185443 A158523 A001615` `Adjacent sequences: A053155 A053156 A053157 * A053159 A053160 A053161`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Feb 29 2000`

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Last modified February 16 19:14 EST 2012. Contains 205945 sequences.