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A068835
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Start of first occurrence of just n consecutive primes with all even digits except the least significant digit.
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0
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2, 23, 41, 821, 4409, 2063, 224401, 8609, 20066003, 20628046223, 82260284069, 2248462002229, 224682444608243
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OFFSET
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1,1
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COMMENTS
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If the least significant digit must be odd, then a(1) = 241.
a(14) > 2*10^15. [From Donovan Johnson, Sep 21 2010]
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LINKS
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Table of n, a(n) for n=1..13.
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EXAMPLE
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a(8) = 8609: the 8 consecutive primes are 8609, 8623, 8627, 8629, 8641, 8647, 8663, 8669.
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MATHEMATICA
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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}]
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CROSSREFS
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Sequence in context: A106736 A045392 A107374 * A156557 A002428 A105440
Adjacent sequences: A068832 A068833 A068834 * A068836 A068837 A068838
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KEYWORD
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more,nonn,base
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 09 2002
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EXTENSIONS
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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
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STATUS
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approved
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