A068830 Smallest member of the first occurrence of exactly n consecutive primes with all odd digits.

97, 31, 71, 191, 311, 53717, 3, 1137911, 3539995913, 379537751, 195513511313, 355993373513, 35795175733111, 139351331937113, 573737391997313

Offset

1,1

Comments

a(16) > (10^16-1)/9. a(17) = 197351535173531. a(n) > (10^16-1)/9 for n >= 18. [Donovan Johnson, Sep 21 2010]

Links

Table of n, a(n) for n=1..15.

Example

a(2) = 31, the two primes are 31 and 37. a(7) = 3 and the primes are 3, 5, 7, 11, 13, 17, and 19.

Mathematica

id[n_] := IntegerDigits[n]; eodQ[n_, i_] := And @@ OddQ[Flatten[id[Table[NextPrime[n, k], {k, 0, i - 1}]]]] && Or @@ EvenQ[id[NextPrime[n, -1]]] && Or @@ EvenQ[id[NextPrime[n, i]]]; Table[n = 2; While[! eodQ[x = Prime[n], i], n++]; x, {i, 8}] (* Jayanta Basu, Aug 08 2013 *)

Crossrefs

Cf. A068831, A068832.

Sequence in context: A247384 A345528 A094498 * A033417 A182690 A088866

Adjacent sequences: A068827 A068828 A068829 * A068831 A068832 A068833

Keyword

hard,more,nonn,base

Author

Amarnath Murthy, Mar 09 2002

Extensions

1137911 from Larry Reeves (larryr(AT)acm.org), Oct 09 2003

a(9)-a(11) from Donovan Johnson, Apr 03 2008

a(12)-a(15) from Donovan Johnson, Sep 21 2010

Status

approved