A075407 - OEIS

A075407

Non-palindromic numbers such that the largest proper divisor is a palindrome having at least two digits and no other divisor is a palindrome with at least two digits.

302, 322, 342, 362, 382, 423, 453, 483, 504, 513, 543, 544, 573, 584, 655, 706, 746, 755, 766, 805, 905, 908, 917, 948, 955, 988, 1029, 1030, 1050, 1057, 1059, 1070, 1090, 1119, 1127, 1130, 1149, 1150, 1170, 1190, 1267, 1312, 1313, 1337, 1352, 1434

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OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000 (terms < 10^6 from David Consiglio, Jr.)

EXAMPLE

322 is here since the divisors of 322 are [1, 2, 7, 14, 23, 46, *161*, 322].

MATHEMATICA

palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse@d]; ok[n_] := Block[{d = Divisors[n]}, Length[d] > 1 && d[[-2]] > 9 && palQ[d[[-2]]] && Length[ Select[d, # > 9 && palQ[#] &, 2]] == 1]; Select[ Range[2000], ok] (* Giovanni Resta, Aug 27 2018 *)

CROSSREFS

Cf. A074888.

Sequence in context: A028499 A145123 A068258 * A258449 A261677 A004227

Adjacent sequences: A075404 A075405 A075406 * A075408 A075409 A075410

KEYWORD

base,nonn

AUTHOR

Jason Earls, Sep 13 2002

EXTENSIONS

Edited by Matthew Conroy, Oct 21 2002

More terms from David Consiglio, Jr., Oct 12 2015

Incorrect Python program deleted by Giovanni Resta, Aug 27 2018

STATUS

approved