id:A053248 - OEIS Search Results

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Second differences of sigma(n) that are negative.

+0
3

1, 4, 10, 9, 11, 30, 10, 20, 40, 32, 16, 65, 13, 42, 82, 46, 12, 96, 26, 82, 106, 46, 18, 143, 57, 70, 114, 88, 40, 214, 26, 66, 136, 88, 120, 244, 30, 60, 160, 171, 47, 256, 36, 150, 266, 96, 40, 286, 88, 176, 226, 124, 12, 24, 342, 170, 230, 222, 94, 34, 443, 71 (list; graph; listen)

	OFFSET	`1,2`
	FORMULA	`a(n) = A053223(A053229(n))`
	MAPLE	`with (numtheory): f := [seq( sigma(i+2) - sigma(i+1) - (sigma(i+1) - sigma(i)), i=1..200)];` seq(`if`(f[i] < 0, f[i], print( )), i=1..200);
	CROSSREFS	`Cf. A000203, A053223, A053247.` `Sequence in context: A070295 A123483 A073722 this_sequence A081547 A111072 A045855` `Adjacent sequences: A053245 A053246 A053247 this_sequence A053249 A053250 A053251`
	KEYWORD	`nonn`
	AUTHOR	`Asher Auel (asher.auel(AT)reed.edu) Jan 11, 2000`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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