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A072415 a(1) = 2; a(n) = a(n-1)-th even nontotient number. 2
2, 26, 182, 878, 3626, 13508, 46922, 155156, 494468, 1529590, 4615074, 13633310, 39548078, 112918434, 317920082, 883996002 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..16.

FORMULA

a(3)=182 is the 26th = a(2)-th term in A005277.

MATHEMATICA

a = Table[0, {10^6}]; Do[b = EulerPhi[n]/2; If[b < 10^6 + 1, a[[b]] = 1], {n, 1, 2 10^7}]; b = Select[ Range[10^6], a[[ # ]] == 0 &]; c = 1; Do[ Print[c]; c = 2b[[c]], {n, 0, 8}]

CROSSREFS

Cf. A006508, A071255, A005277, A072416.

Sequence in context: A153913 A246586 A067851 * A197468 A184354 A178884

Adjacent sequences:  A072412 A072413 A072414 * A072416 A072417 A072418

KEYWORD

more,nonn

AUTHOR

Labos Elemer, Jun 17 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jun 20 2002

a(11)-a(16) from Donovan Johnson, Oct 29 2010

STATUS

approved

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Last modified May 16 19:46 EDT 2021. Contains 343951 sequences. (Running on oeis4.)