

A083536


First differences of noncototients A005278.


5



16, 8, 16, 2, 6, 28, 14, 16, 6, 8, 4, 12, 8, 16, 2, 14, 16, 4, 12, 4, 10, 12, 16, 6, 2, 6, 16, 2, 6, 12, 16, 14, 4, 2, 16, 4, 6, 14, 8, 10, 8, 24, 30, 4, 4, 8, 8, 28, 2, 12, 2, 2, 10, 8, 8, 4, 14, 4, 12, 30, 8, 16, 2, 14, 14, 6, 2, 10, 8, 16, 2, 6, 2, 14, 26, 6, 8, 8, 14, 10, 16, 8, 8, 22, 2, 28
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Table of n, a(n) for n=1..86.


FORMULA

a(n) = A005278(n+1)  A005278(n).


EXAMPLE

Missing terms from A051953 are 10,26,34,50,.. so their difference sequence starts with 16,8,16,...


MATHEMATICA

t0[x_] := Table[j, {j, 1, x}] t=Table[wEulerPhi[w], {w, 1, 10000}]; u=Union[%]; Delete[uRotateRight[u], 1]; c=Complement[t0[10000], u]; Delete[cRotateRight[c], 1];


CROSSREFS

Cf. A051953, A005278.
Sequence in context: A102272 A304227 A305037 * A305583 A316690 A258160
Adjacent sequences: A083533 A083534 A083535 * A083537 A083538 A083539


KEYWORD

nonn


AUTHOR

Labos Elemer, May 20 2003


EXTENSIONS

a(84)a(85) corrected by David Ng, (an error that was noticed by Doug Phillips), Oct 31 2016
a(86) corrected and name simplified by Omar E. Pol, Nov 04 2016


STATUS

approved



