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A077652

Primes whose initial and terminal decimal digits are identical.

2, 3, 5, 7, 11, 101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929, 1021, 1031, 1051, 1061, 1091, 1151, 1171, 1181, 1201, 1231, 1291, 1301, 1321, 1361, 1381, 1451, 1471, 1481, 1511, 1531, 1571, 1601, 1621, 1721, 1741, 1801, 1811

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OFFSET

1,1

COMMENTS

1021 is the smallest of these not to be palindromic. - Jonathan Vos Post, Nov 02 2013

All palindromic primes (A002385) except 11 have an odd number of digits, therefore all terms > 11 with an even number of digits are non-palindromic in this sequence. - M. F. Hasler, Nov 02 2013

LINKS

Bruno Berselli, Table of n, a(n) for n = 1..1000

MATHEMATICA

Do[s1=First[IntegerDigits[Prime[n]]]; s2=Last[IntegerDigits[Prime[n]]]; If[Equal[s1, s2], Print[Prime[n]]], {n, 1, 1000}]

itdQ[n_]:=Module[{idn=IntegerDigits[n]}, idn[[1]]==idn[[-1]]]; Select[Prime[ Range[ 500]], itdQ] (* Harvey P. Dale, Apr 12 2013 *)

PROG

(Magma) [ p: p in PrimesUpTo(2000) | P[#P] eq P[1] where P is Intseq(p) ]; // Bruno Berselli, Jul 26 2011

(PARI) is(n)=digits(n)[1]==n%10&&isprime(n) \\ M. F. Hasler, Nov 02 2013

CROSSREFS

Cf. A000030, A000040, A227858.

Sequence in context: A234912 A083137 A180440 * A002385 A069217 A083139

Adjacent sequences: A077649 A077650 A077651 * A077653 A077654 A077655

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Nov 19 2002

STATUS

approved