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A071251 Squarefree palindromes. 1
1, 2, 3, 5, 6, 7, 11, 22, 33, 55, 66, 77, 101, 111, 131, 141, 151, 161, 181, 191, 202, 222, 262, 282, 303, 313, 323, 353, 373, 383, 393, 434, 454, 474, 494, 505, 515, 535, 545, 555, 565, 595, 606, 626, 646, 707, 717, 727, 737, 757, 767, 777, 787, 797, 818, 838 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..56.

MAPLE

ffpal := proc(n) local i, j, k, s, aa, nn, bb, flag; s := n; aa := convert(s, string); nn := length(aa); bb := ``; for i from nn by -1 to 1 do bb := cat(bb, substring(aa, i..i)); od; flag := 0; for j from 1 to nn do if substring(aa, j..j)<>substring(bb, j..j) then flag := 1 fi; od; RETURN(flag); end: ts_ndk_pal := proc(i) if ffpal((i)) = 0 then if (numtheory[issqrfree](i) = 'true' ) then RETURN((i)) fi fi end: andkpal := [seq(ts_ndk_pal(i), i=1..10000)]: andkpal;

MATHEMATICA

Select[ Range[ 1000], # == FromDigits[ Reverse[ IntegerDigits[ # ]]] && Max[ Transpose[ FactorInteger[ # ]] [[2]]] < 2 &]

CROSSREFS

Cf. A002385, A069217, A032350, A005117, A035132.

Sequence in context: A062084 A273524 A098959 * A077571 A101730 A276692

Adjacent sequences:  A071248 A071249 A071250 * A071252 A071253 A071254

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, May 21 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jun 03 2002

STATUS

approved

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Last modified February 21 02:19 EST 2018. Contains 299388 sequences. (Running on oeis4.)