A096504 - OEIS

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A096504

Euler-phi applied to A096503 results in these decimal repdigits.

1, 1, 2, 2, 4, 2, 6, 4, 6, 4, 4, 6, 8, 8, 6, 8, 22, 8, 8, 22, 66, 44, 88, 44, 88, 66, 44, 88, 88, 222, 88, 88, 222, 444, 444, 888, 888, 444, 888, 888, 888, 888, 888, 888, 444444, 666666, 444444, 888888, 888888, 666666, 888888, 888888, 888888, 888888, 888888

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..182 (calculated using the b-file at A096503)

FORMULA

a(n) = A000010(A096503(n)).

EXAMPLE

a(60) = A000010(A096503(60)) = A000010(88888892) = 44444444.

Regular solutions: if p = repdigit + 1 is prime, then phi(p) = repdigit.

PROG

(PARI) lista(nn) = {for (n= 1, nn, phin = eulerphi(n); d = digits(e=eulerphi(n)); if (vecmin(d) == vecmax(d), print1(e, ", ")); ); } \\ Michel Marcus, Sep 07 2014

CROSSREFS

Cf. A000010, A010785, A096503, A096505.

Sequence in context: A004085 A293482 A086296 * A277906 A290077 A277030

Adjacent sequences: A096501 A096502 A096503 * A096505 A096506 A096507

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Jul 12 2004

STATUS

approved