The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A100957 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. 3
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..200 MATHEMATICA 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}] CROSSREFS Cf. A100026, A100955, A100956. Sequence in context: A103713 A197184 A089129 * A191856 A220862 A198229 Adjacent sequences:  A100954 A100955 A100956 * A100958 A100959 A100960 KEYWORD base,nonn AUTHOR Robert G. Wilson v, Nov 23 2004 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 12 21:10 EDT 2020. Contains 336440 sequences. (Running on oeis4.)