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 A077391 Smallest n-digit prime which leaves a prime at every step if most significant digit and least significant digit are deleted until a one digit or two digit prime is obtained, or 0 if no such prime exists. 0
 2, 11, 127, 1021, 10313, 100237, 1002931, 10002331, 100023331, 1000023337, 10000239937, 100000233397, 1000002339937, 10000002339931, 100000139991331, 1000000023399331, 10000000233993397, 100000000293999997 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Conjecture: No term is zero. LINKS Table of n, a(n) for n=1..18. EXAMPLE a(6) = 100237: this is the smallest 6-digit number such that deleting MSD and LSD yields prime at every step, i.e. 100237, 0023, 02 all are primes. CROSSREFS Cf. A077390. Sequence in context: A206401 A193207 A112864 * A104087 A208858 A283537 Adjacent sequences: A077388 A077389 A077390 * A077392 A077393 A077394 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 07 2002 EXTENSIONS More terms from Daniel Starodubtsev, May 05 2020 STATUS approved

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Last modified June 13 15:51 EDT 2024. Contains 373389 sequences. (Running on oeis4.)