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Search: id:A100957
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| A100957 |
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Consider all (2n+1)-digit palindromic primes of the form 90...0M0...09 (so that M is a palindrome with <= 2n-1 digits); a(n) = smallest such M. |
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+0
3
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| 1, 7, 2, 1, 2, 5, 838, 232, 121, 8, 151, 202, 2, 101, 646, 5, 1, 151, 424, 404, 242, 131, 646, 272, 16361, 1, 494, 1, 868, 101, 494, 12421, 14041, 151, 595, 383, 515, 19091, 10001, 242, 17171, 20602, 161, 292, 11011, 8, 1, 11611, 22822, 232, 17771, 616, 767
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OFFSET
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1,2
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MATHEMATICA
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f[n_] := Block[{k = 0, t = Flatten[ Join[{9}, Table[0, {n - 1}]]]}, While[s = Drop[t, Min[ -Floor[ Log[10, k]/2], 0]]; k != FromDigits[ Reverse[ IntegerDigits[k]]] || !PrimeQ[ FromDigits[ Join[s, IntegerDigits[k], Reverse[s]]]], k++ ]; k]; Table[ f[n], {n, 55}]
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CROSSREFS
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Cf. A100026, A100955, A100956.
Adjacent sequences: A100954 A100955 A100956 this_sequence A100958 A100959 A100960
Sequence in context: A021585 A103713 A089129 this_sequence A133362 A010140 A060991
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KEYWORD
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base,nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 23 2004
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