login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A053237 Numbers n such that both A053230(n) and A053230(n+1) = 1. 7
1, 31, 38, 67, 74, 98, 128, 197, 228, 240, 247, 277, 283, 307, 313, 332, 339, 369, 382, 400, 413, 430, 459, 489, 502, 520, 551, 609, 622, 646, 664, 729, 759, 771, 823, 830, 843, 908, 915, 940, 969, 1038, 1057, 1086, 1117, 1124, 1148, 1206, 1247, 1266, 1290 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Pairs of consecutive 1's occur uncommonly often in A053230.

LINKS

Table of n, a(n) for n=1..51.

MAPLE

with(numtheory): f := [seq( `if`((sigma(i+1) > sigma(i)), i, print( )), i=1..5000)];

seq(`if`((f[i+2]-f[i+1]=1) and (f[i+1]-f[i]=1), i, print( )), i=1..1500);

CROSSREFS

Cf. A000203, A053224, A053230, A053231, A053232, A053233, A053234, A053235, A053236.

Sequence in context: A062213 A097759 A247251 * A039378 A043201 A043981

Adjacent sequences:  A053234 A053235 A053236 * A053238 A053239 A053240

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu), Jan 10 2000

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 June 13 20:25 EDT 2021. Contains 345009 sequences. (Running on oeis4.)