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!)
A154313 Numbers n such that abs(A007605(n) - A007953(n)) < 2. 1

%I #11 Sep 10 2016 14:41:00

%S 1,2,7,13,16,29,32,38,53,54,56,63,66,68,69,76,88,94,126,156,175,176,

%T 182,183,191,192,212,213,218,227,248,252,255,258,259,280,282,286,291,

%U 293,294,295,298,306,307,321,323,324,325,326,331,334,335,338,345,348

%N Numbers n such that abs(A007605(n) - A007953(n)) < 2.

%C Also, numbers n such that abs(A090431(n)) < 2. - _Omar E. Pol_, Jan 12 2009

%H G. C. Greubel and Charles R Greathouse IV, <a href="/A154313/b154313.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Greubel)

%e If n = 16 then prime(n) = 53 and abs((5+3)-(1+6)) = 8-7 = 1, so 16 is in the sequence.

%t Select[Range[500], Abs[Apply[Plus, RealDigits[Prime[#]][[1]]] - Sum[DigitCount[#][[i]]*i, {i, 9}]] < 2 &] (* _G. C. Greubel_, Sep 10 2016 *)

%o (PARI) list(lim)=my(v=List(),n); forprime(p=2,, if(n++>lim,break); if(abs(sumdigits(n)-sumdigits(p))<2, listput(v,n))); Vec(v) \\ _Charles R Greathouse IV_, Sep 10 2016

%Y Cf. A000040, A141468, A007605, A007953, A090431.

%K nonn,base,easy

%O 1,2

%A _Juri-Stepan Gerasimov_, Jan 07 2009

%E Corrected and edited by _Omar E. Pol_, Jan 12 2009

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 March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)