login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A283550 Numbers that are not the sum of abundant numbers (not necessarily distinct). 3
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 28, 29, 31, 33, 34, 35, 37, 39, 41, 43, 45, 46, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(496) = 991 is the last term.

Subsequence of A048242 (Numbers that are not the sum of two abundant numbers).

Giovanni Resta noticed that 991 is the largest number that is not a sum of abundant numbers.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..496

Giovanni Resta, abundant numbers

EXAMPLE

20161 = 12 + 304 + 19845 is the sum of 3 abundant numbers and thus not in the sequence (although it is in A048242, since it is not the sum of 2 abundant numbers).

MATHEMATICA

AbundantQ[n_] := DivisorSigma[1, n] > 2 n; a = Select[Range[1000], AbundantQ[#] &]; nn = Dimensions[a][[1]]; t = Rest[CoefficientList[ Series[Product[(1 + x^a[[k]]), {k, nn}], {x, 0, a[[-1]]}], x]]; f = Flatten[Position[t, 0]]

CROSSREFS

Cf. A271113, A048242, A005101.

Sequence in context: A285100 A067340 A263837 * A271113 A325369 A317101

Adjacent sequences:  A283547 A283548 A283549 * A283551 A283552 A283553

KEYWORD

nonn,fini,full

AUTHOR

Amiram Eldar, Mar 10 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 21 17:20 EDT 2019. Contains 325198 sequences. (Running on oeis4.)