login
Nachos sequence based on 1 plus primes (A008578).
4

%I #19 Mar 05 2017 15:13:56

%S 1,2,1,2,3,1,2,3,2,3,1,2,3,2,3,4,2,1,2,3,2,3,4,2,3,4,3,4,1,2,3,2,3,4,

%T 2,3,4,3,4,2,3,1,2,3,2,3,4,2,3,4,3,4,2,3,4,3,4,5,1,2,3,2,3,4,2,3,4,3,

%U 4,2,3,4,3,4,5,3,2,1,2,3,2,3,4,2,3,4,3,4,2,3,4,3,4,5,3,2,3,4,3

%N Nachos sequence based on 1 plus primes (A008578).

%C Like A280053 but based on 1,2,3,5,7,11,... rather than squares. See that entry for further information.

%C Equivalently, greedily subtract terms of A014284 from n until reaching 0; a(n) = number of steps required.

%H Lars Blomberg, <a href="/A280055/b280055.txt">Table of n, a(n) for n = 1..10000</a>

%e 26 takes 4 phases to read 0:

%e subtract leaves

%e 1 25

%e 2 23

%e 3 20

%e 5 15

%e 7 8

%e ------

%e 1 7

%e 2 5

%e 3 2

%e ------

%e 1 1

%e ------

%e 1 0

%e so a(26) = 4

%p A280055 := proc(n)

%p local a,nres,i ;

%p a := 0 ;

%p nres := n;

%p while nres > 0 do

%p for i from 1 do

%p if A014284(i) > nres then

%p break;

%p end if;

%p end do:

%p nres := nres-A014284(i-1) ;

%p a := a+1 ;

%p end do:

%p a ;

%p end proc:

%p seq(A280055(n),n=1..80) ; # _R. J. Mathar_, Mar 05 2017

%Y Cf. A280055, A014284.

%Y For records see A280760.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Jan 08 2017