A046883 - OEIS

A046883

Automorphic primes: primes p such that p is k-th prime and p ends in k.

17, 99551, 4303027, 6440999, 14968819, 95517973, 527737957, 1893230839, 1246492090901, 12426836115943, 21732382677641, 154895576080181, 2677628540590583, 133475456543097857, 820396537622790811

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OFFSET

1,1

COMMENTS

a(13) > 10^15. - Donovan Johnson, Mar 26 2010

LINKS

Table of n, a(n) for n=1..15.

Index entries for sequences related to automorphic numbers

EXAMPLE

p(7)=17, p(9551)=99551, p(303027)=4303027, p(440999)=6440999, p(968819)=14968819, p(5517973)=95517973.

MATHEMATICA

Do[ If[ Mod[ Prime[n], 10^Ceiling[ Log[10, n]]] == n, Print[Prime[n]]], {n, 1, 100000000, 2}] (* Robert G. Wilson v, May 21 2004 *) (* fixed by Ivan N. Ianakiev, Apr 15 2022 *)

fQ[n_]:=StringPosition[ToString[Prime[n]], ToString[n]][[1, 2]]==

IntegerLength[Prime[n]]; Prime[Select[Range[1, 5517973, 2], fQ]]//Quiet (* Ivan N. Ianakiev, Apr 15 2022 *)

CROSSREFS

Cf. A067248, A068575, A075902, A046884.

Sequence in context: A075902 A013760 A078351 * A046884 A269442 A203677

Adjacent sequences: A046880 A046881 A046882 * A046884 A046885 A046886

KEYWORD

base,nice,nonn

AUTHOR

Felice Russo and Carlos Rivera

EXTENSIONS

One more term from Zak Seidov, Sep 27 2002

Corrected by Lior Manor, Oct 14 2002

a(7)-a(8) from Robert G. Wilson v, May 21 2004

a(9)-a(12) from Donovan Johnson, Mar 26 2010

a(13)-a(14) from Chai Wah Wu, Apr 05 2021

a(15) from Chai Wah Wu, Apr 07 2021

STATUS

approved