

A089182


Prime digit palindromes 2,...,23577532 continued by adding 10^(nk) and 10^(k1) times prime(k).


1



2, 22, 232, 2332, 23532, 235532, 2357532, 23577532, 235817532, 2358217532, 23582417532, 235824417532, 2358248417532, 23582488417532, 235824908417532, 2358249108417532, 23582491508417532, 235824915508417532
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OFFSET

1,1


COMMENTS

Original definition: Overlapping primebased palindromic sequence.
Only the first 8 terms are truly palindromes: a modulo 10 version of this would work with a limited digit set {1,2,3,5,7,9} with 2 and 5 only occuring as 1st and 3rd digit to either side.


LINKS

Table of n, a(n) for n=1..18.


FORMULA

a(n) = Sum_{k=1..floor(n/2)} prime(k)*(10^(nk) + 10^(k1)) + (n mod 2)*prime((n+1)/2)*10^floor(n/2).  M. F. Hasler, Apr 06 2009


MATHEMATICA

a[m_]=Delete[Table[If [ Floor[m/2]n>=0, Prime[ n], Prime[mn]], {n, 1, m}], m] b=Table[Sum[a[m][[i]]*10^(i1), {i, 1, m1}], {m, 2, digits}]


CROSSREFS

Cf. A007907, A138140.
Sequence in context: A002276 A112893 A086855 * A138140 A322283 A151617
Adjacent sequences: A089179 A089180 A089181 * A089183 A089184 A089185


KEYWORD

nonn,base


AUTHOR

Roger L. Bagula, Dec 07 2003


EXTENSIONS

Edited by M. F. Hasler, Apr 06 2009


STATUS

approved



