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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[w-EulerPhi[w], {w, 1, 10000}]; u=Union[%]; Delete[u-RotateRight[u], 1]; c=Complement[t0[10000], u]; Delete[c-RotateRight[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

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Last modified January 23 22:16 EST 2020. Contains 331177 sequences. (Running on oeis4.)