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!)
A112265 Cumulative sum of sum of initial digits of prime factors (with multiplicity) of n. 3

%I

%S 0,2,5,9,14,19,26,32,38,45,46,53,54,63,71,79,80,88,89,98,108,111,113,

%T 122,132,135,144,155,157,167,170,180,184,187,199,209,212,215,219,230,

%U 234,246,250,255,266,270,274,285,299,311,315,320,325,336,342,355,359

%N Cumulative sum of sum of initial digits of prime factors (with multiplicity) of n.

%C Primes in this sequence are A112266.

%H G. C. Greubel, <a href="/A112265/b112265.txt">Table of n, a(n) for n = 1..1000</a>

%F a(1) = 0 and given the prime factorization i = (p_1)^(e_1) * (p_2)^(e_2) * ... * (p_k)^(e_k) then a(n) = Sim_{i=1..n} A112264(i) = Sum_{i=1..n} (e_1)*A000030(p_1) + (e_2)*A000030(p_2) + ... + (e_k)*A000030(p_l).

%t f[1] = 0; f[n_] := Plus @@ (#[[2]] First@IntegerDigits[#[[1]]] & /@ FactorInteger[n]); Accumulate@ Array[f, 90] (* _Giovanni Resta_, Jun 17 2016 *)

%Y Cf. A000030, A000040, A001221, A001222, A112264, A112266 to A112273.

%K base,easy,nonn

%O 1,2

%A _Jonathan Vos Post_, Aug 30 2005

%E Corrected and edited by _Giovanni Resta_, Jun 17 2016

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 2 16:02 EDT 2020. Contains 335404 sequences. (Running on oeis4.)