id:A053247 - OEIS Search Results

Search: id:A053247

Displaying 1-1 of 1 results found.

page 1

Second differences of sigma(n) that are positive.

+0
3

2, 7, 11, 7, 22, 24, 7, 34, 41, 14, 48, 40, 18, 68, 71, 21, 49, 75, 38, 102, 92, 100, 103, 47, 110, 96, 50, 138, 140, 15, 103, 134, 78, 195, 161, 6, 116, 194, 70, 182, 140, 72, 234, 178, 56, 156, 227, 76, 229, 218, 226, 276, 160, 260, 162, 26, 252, 280, 74, 224 (list; graph; listen)

	OFFSET	`1,1`
	FORMULA	`a(n) = A053223(A053228(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, A053248.` `Sequence in context: A100020 A020638 A091385 this_sequence A087723 A136998 A136734` `Adjacent sequences: A053244 A053245 A053246 this_sequence A053248 A053249 A053250`
	KEYWORD	`nonn`
	AUTHOR	`Asher Auel (asher.auel(AT)reed.edu) Jan 11, 2000`

page 1

Search completed in 0.002 seconds

Last modified December 16 17:18 EST 2009. Contains 170825 sequences.

AT&T Labs Research