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A068835 Start of first occurrence of just n consecutive primes with all even digits except the least significant digit. 0
2, 23, 41, 821, 4409, 2063, 224401, 8609, 20066003, 20628046223, 82260284069, 2248462002229, 224682444608243 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If the least significant digit must be odd, then a(1) = 241.
a(14) > 2*10^15. [From Donovan Johnson, Sep 21 2010]
LINKS
EXAMPLE
a(8) = 8609: the 8 consecutive primes are 8609, 8623, 8627, 8629, 8641, 8647, 8663, 8669.
MATHEMATICA
a = {0, 1, 1, 1}; Do[ If[ Union[ EvenQ[ Drop[ IntegerDigits[ Prime[n]], -1]]] == {True}, a = Append[a, 1], a = Append[a, 0]], {n, 5, 10^5}]; Do[k = 3; b = Table[1, {n}]; b = Insert[b, 0, {{1}, {-1}}]; While[k < 10^5 - n && Take[a, {k - 1, k + n}] != b, k++ ]; If[k < 10^5, Print[ Prime[k]], Print[0]], {n, 1, 8}]
CROSSREFS
Sequence in context: A106736 A045392 A107374 * A156557 A002428 A325145
KEYWORD
more,nonn,base
AUTHOR
Amarnath Murthy, Mar 09 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Apr 10 2002
a(9)-a(12) from Donovan Johnson, Sep 03 2008
a(13) from Donovan Johnson, Sep 21 2010
STATUS
approved

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Last modified March 19 07:18 EDT 2024. Contains 370954 sequences. (Running on oeis4.)