A114755 Smallest prime of the form: n successive positive integers in ascending order followed by a 3. a(3k) = 0 as no such prime exists.

13, 233, 0, 12343, 345673, 0, 5678910113, 54555657585960613, 0, 373839404142434445463, 17181920212223242526273, 0, 2345678910111213143, 23242526272829303132333435363, 0, 8910111213141516171819202122233

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Example

a(4) = 12343, four successive positive integers 1,2,3,4 in ascending order followed by a 3.

Mathematica

a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={}; Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]); !PrimeQ[10FromDigits[v]+3], m++ ]; 10FromDigits[v]+3)]; Table[a[n], {n, 17}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, If[ Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {3}]; !PrimeQ@p, t++ ]; p]]; Array[f, 20] (* Robert G. Wilson v *)

Crossrefs

Cf. A114754, A114756, A114757, A114758, A114759, A112716, A108145.

Sequence in context: A176722 A083081 A083306 * A142610 A218202 A134493

Adjacent sequences: A114752 A114753 A114754 * A114756 A114757 A114758

Keyword

base,nonn

Author

Amarnath Murthy, Jan 01 2006

Extensions

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

Status

approved