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A076528 Numbers n such that sigma(n) = sigma(n-1) - sigma(n-2). 2
955, 1301, 11143, 38215, 89485, 152155, 167785, 254137, 303281, 473317, 574717, 813921, 918081, 1307023, 2008361, 3676243, 9878245, 10368513, 12548755, 19411481, 22493263, 42413485, 77766487, 81513817, 157874001, 240828973 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..170 (terms < 10^13)

FORMULA

a(n) = A073500(n)+1 - Alex Ratushnyak, Jul 06 2013.

EXAMPLE

sigma(955) = 1152 sigma(954) = 2106 sigma(953) = 954 and 1152 = 2106 - 954; hence 955 is a term of the sequence.

MATHEMATICA

Select[Range[3, 10^5], DivisorSigma[1, # ] == DivisorSigma[1, # - 1] - DivisorSigma[1, # - 2] &]

CROSSREFS

Cf. A000203, A073500.

Sequence in context: A055161 A055158 A187635 * A260067 A031903 A226851

Adjacent sequences:  A076525 A076526 A076527 * A076529 A076530 A076531

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Oct 18 2002

EXTENSIONS

a(6)-a(26) from Donovan Johnson, Feb 01 2009

STATUS

approved

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Last modified August 12 16:40 EDT 2020. Contains 336439 sequences. (Running on oeis4.)