The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A303741 Numbers k such that A(k+1) = A(k) + 2, where A() = A005101() are the abundant numbers. 4
2, 7, 10, 14, 16, 19, 22, 23, 26, 31, 36, 39, 44, 45, 48, 51, 52, 59, 62, 65, 70, 71, 74, 79, 81, 82, 83, 86, 87, 90, 93, 96, 99, 104, 107, 110, 111, 114, 118, 120, 125, 128, 131, 133, 135, 138, 141, 146, 149, 150, 155, 156, 158, 164, 169, 170, 175, 178, 179 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..5000 from Muniru A Asiru)
FORMULA
Sequence is { k | A005101(k+1) = A005101(k) + 2 }.
MAPLE
with(numtheory): A:=select(n->sigma(n)>2*n, [$1..1000]): a:=select(j->A[j+1]=A[j]+2, [$1..nops(A)-1]);
MATHEMATICA
Position[Differences[Select[Range[750], DivisorSigma[1, #] > 2*# &]], 2] // Flatten (* Amiram Eldar, Mar 15 2024 *)
PROG
(GAP) A:=Filtered([1..1000], n->Sigma(n)>2*n);; a:=Filtered([1..Length(A)-1], i->A[i+1]=A[i]+2);
CROSSREFS
A231086 is the main entry for this sequence.
Sequence in context: A297832 A003158 A130336 * A085303 A304799 A349499
KEYWORD
nonn
AUTHOR
Muniru A Asiru, Jun 22 2018
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 23 18:13 EDT 2024. Contains 372765 sequences. (Running on oeis4.)