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!)
A082097 a(n) = d(a(n-1)) + n = A000005(a(n-1)) + n, with a(1)=1. 1
1, 1, 1, 5, 7, 8, 11, 10, 13, 12, 17, 14, 17, 16, 20, 22, 21, 22, 23, 22, 25, 25, 26, 28, 31, 28, 33, 32, 35, 34, 35, 36, 42, 42, 43, 38, 41, 40, 47, 42, 49, 45, 49, 47, 47, 48, 57, 52, 55, 54, 59, 54, 61, 56, 63, 62, 61, 60, 71, 62, 65, 66, 71, 66, 73, 68, 73, 70, 77, 74 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

MAPLE

with(numtheory);

a:= proc(n) option remember;

   if n < 4 then 1

   else tau(a(n-1)) + n

   fi

end:

seq(a(n), n=1..70); # G. C. Greubel, Aug 31 2019

MATHEMATICA

a[n_]:= If[n<4, 1, DivisorSigma[0, a[n-1]] + n]; Table[a[n], {n, 70}] (* modified by G. C. Greubel, Aug 31 2019 *)

PROG

(PARI) a(n) = if(n<4, 1, numdiv(a(n-1)) + n); \\ G. C. Greubel, Aug 31 2019

(MAGMA) a:= func< n | n lt 4 select 1 else n + NumberOfDivisors(Self(n-1)) >;

[a(n): n in [1..70]]; // G. C. Greubel, Aug 31 2019

(Sage)

def a(n):

    if n<4: return 1

    else: return sigma(a(n-1), 0) + n

[a(n) for n in (1..70)] # G. C. Greubel, Aug 31 2019

(GAP)

a:= function(n)

    if n<4 then return 1;

    else return Tau(a(n-1)) + n;

    fi;

  end;

List([1..70], n-> a(n) ); # G. C. Greubel, Aug 31 2019

CROSSREFS

Cf. A069103, A082094, A082095, A082096.

Sequence in context: A192270 A056657 A068312 * A088299 A287068 A013635

Adjacent sequences:  A082094 A082095 A082096 * A082098 A082099 A082100

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 11 2003

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 February 27 07:07 EST 2020. Contains 332300 sequences. (Running on oeis4.)