A113622 - OEIS

A113622

Numbers k such that the reverse of the representation of phi(k) is a substring of k, in base 10.

1, 21, 63, 270, 291, 1065, 2991, 6102, 10087, 10279, 10654, 16528, 144069, 1440069, 10253179, 10657654, 14400069, 16163608, 46676013, 69460293, 2346534651, 2369436474, 6313047393, 10270341004, 10657657654, 14406534069, 23400000651

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OFFSET

1,2

COMMENTS

If p = 480...023 is prime, then k = 3*p = 1440...069 and phi(k) = 960...044, thus k belongs to the sequence.

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

phi(1_440069) = 960044.

MATHEMATICA

lst = {}; Do[If[{}!= StringPosition[ToString@n, StringReverse@ToString@EulerPhi@n], AppendTo[lst, n], {n, 2*10^7}]; lst

CROSSREFS

Cf. A000010, A069215.

Sequence in context: A033850 A251213 A170930 * A069215 A115921 A251808

Adjacent sequences: A113619 A113620 A113621 * A113623 A113624 A113625

KEYWORD

base,nonn

AUTHOR

Giovanni Resta, Jan 26 2006

EXTENSIONS

a(19)-a(27) from Donovan Johnson, May 11 2010

STATUS

approved