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A053226 n for which sigma(n) > sigma(n+1). 12
4, 6, 8, 10, 12, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 56, 58, 60, 64, 66, 68, 70, 72, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 105, 106, 108, 110, 112, 114, 116, 117, 118, 120, 122, 124, 126, 128, 130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

MAPLE

with(numtheory): seq( `if`((sigma(i) > sigma(i+1)), i, print( )), i=1..139);

MATHEMATICA

Select[Range[150], DivisorSigma[1, #] > DivisorSigma[1, # + 1] &] (* Carl Najafi, Aug 16 2011 *)

PROG

(Haskell)

import Data.List (findIndices)

a053226 n = a053226_list !! (n-1)

a053226_list = map (+ 1) $ findIndices (< 0) a053222_list

-- Reinhard Zumkeller, Oct 16 2011

(PARI) is(n)=sigma(n)>sigma(n+1) \\ Charles R Greathouse IV, Mar 09 2014

CROSSREFS

Cf. A000203, A053222, A053224, A053238.

Sequence in context: A193167 A020645 A051756 * A227112 A074827 A068354

Adjacent sequences:  A053223 A053224 A053225 * A053227 A053228 A053229

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu) Jan 06 2000

STATUS

approved

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Last modified December 21 10:08 EST 2014. Contains 252304 sequences.