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A125115 Differences between consecutive abundant numbers. 6
6, 2, 4, 6, 6, 4, 2, 6, 6, 2, 4, 6, 4, 2, 6, 2, 4, 4, 2, 6, 4, 2, 2, 4, 4, 2, 6, 6, 6, 6, 2, 4, 6, 6, 4, 2, 6, 6, 2, 4, 6, 6, 4, 2, 2, 4, 4, 2, 6, 4, 2, 2, 4, 6, 6, 6, 6, 6, 2, 4, 6, 2, 4, 4, 2, 6, 6, 6, 4, 2, 2, 4, 6, 2, 4, 6, 6, 4, 2, 6, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

One may think that a(n) is always even and greater than 1. This is not the case as can be seen with A096399 or A228382. - Michel Marcus, Aug 21 2013

LINKS

Muniru A Asiru, Table of n, a(n) for n = 1..10000

EXAMPLE

a(1) = 6 because 18 - 12 = 6; a(4) = 6 because 30 - 24 = 6.

MATHEMATICA

#[[2]] - #[[1]]&/@Partition[Select[Range[300], DivisorSigma[1, #] > 2# &], 2, 1] (* Harvey P. Dale, Dec 02 2006 *)

Differences[Select[Range[300], DivisorSigma[1, #] > 2# &]] (* Alonso del Arte, Apr 29 2019 *)

PROG

(PARI) lista(nn) = {lastab = 0; for (i=1, nn, if (sigma(i) > 2*i, if (lastab, print1(i - lastab, ", ")); lastab = i; ); ); } \\ Michel Marcus, Aug 21 2013

(GAP) A:=Filtered([1..350], n->Sigma(n)>2*n);;  a:=List([1..Length(A)-1], i->A[i+1]-A[i]); # Muniru A Asiru, Jun 09 2018

CROSSREFS

Cf. A005101, A096399, A228382.

Sequence in context: A010493 A175286 A061496 * A202244 A257535 A020831

Adjacent sequences:  A125112 A125113 A125114 * A125116 A125117 A125118

KEYWORD

easy,nonn

AUTHOR

Jason G. Wurtzel, Nov 21 2006

EXTENSIONS

More terms from Michel Marcus, Aug 21 2013

STATUS

approved

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Last modified January 23 22:16 EST 2020. Contains 331177 sequences. (Running on oeis4.)