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A068839 Smallest prime that ends with the right concatenation of first n odd numbers. 1
11, 31, 1531, 67531, 1397531, 311197531, 16131197531, 2515131197531, 71715131197531, 33191715131197531, 7621191715131197531, 232321191715131197531, 7252321191715131197531 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

a(5) = 1397531 which contains as trailing digits the right concatenation of first 5 odd numbers 97531.

MATHEMATICA

a068839[n_] := Module[{}, a1=Flatten[Table[IntegerDigits[i], {i, n, 1, -2}]]; FromDigits[pref=1; a2=a1; While[ !PrimeQ[FromDigits[a2]], a2=Join[IntegerDigits[pref], a1]; pref+=1]; a2]]; Table[a068839[i], {i, 1, 33, 2}]

CROSSREFS

Cf. A068837, A068838.

Sequence in context: A111015 A143765 A023306 * A177360 A060857 A045982

Adjacent sequences:  A068836 A068837 A068838 * A068840 A068841 A068842

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 10 2002

EXTENSIONS

More terms from Vit Planocka (planocka(AT)mistral.cz), Oct 18 2002

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Last modified February 15 02:38 EST 2012. Contains 205689 sequences.