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A114758 Smallest prime of the form: n successive positive integers in descending order followed by a 1. 8
11, 211, 5431, 76541, 17161514131, 1211109871, 98765431, 876543211, 9876543211, 242322212019181716151, 11109876543211, 1131121111101091081071061051041031021, 555453525150494847464544431 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

a(4) = 76541, four successive positive integers 7,6,5,4 in descending order followed by a 1.

MATHEMATICA

a[n_]:=(For[m=1, (v={}; Do[v=Join[v, IntegerDigits[k]], {k, m+n-1, m, -1}]); !PrimeQ[10FromDigits[v]+1], m++ ]; 10FromDigits[v]+1); Table[a[n], {n, 14}] - Farideh Firoozbakht

f[n_] := Block[{t = Reverse@Range@n}, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {1}]; ! PrimeQ@p, t++ ]; p]; Array[f, 13] (* Robert G. Wilson v *)

CROSSREFS

Cf. A113514, A114754, A114755, A114756, A114757, A114759, A112716, A108145, A114761.

Sequence in context: A110747 A112704 A243674 * A088061 A070220 A134069

Adjacent sequences:  A114755 A114756 A114757 * A114759 A114760 A114761

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Jan 01 2006

EXTENSIONS

Extended by Robert G. Wilson v, Ray Chandler and Farideh Firoozbakht, Jan 02 2006

More terms from Robert G. Wilson v, Jan 03 2006

STATUS

approved

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Last modified September 27 18:56 EDT 2021. Contains 347694 sequences. (Running on oeis4.)