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 A096521 Smallest exponent of 2 when the number of primes in the neighborhood of center=2^n and radius=ceiling(log(2^n)) equals n. 2
 25, 9, 1, 2, 20, 18, 127, 844, 573 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS EXAMPLE First in the suitable neighborhood of 2^25 no primes occur: a[0]=25, while corresponding around 2^127 6 primes arise: a[6]=127. MATHEMATICA t=Table[Count[Table[PrimeQ[2^n+i], {i, -Ceiling[Log[2^n]//N], Ceiling[Log[2^n]//N]}], True], {n, 1, 256}] Table[Min[Flatten[Position[t, j]]], {j, 0, 10}] CROSSREFS Cf. A096509-A096523. Sequence in context: A040605 A307179 A065910 * A215539 A224490 A226224 Adjacent sequences:  A096518 A096519 A096520 * A096522 A096523 A096524 KEYWORD nonn,more AUTHOR Labos Elemer, Jul 12 2004 STATUS approved

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Last modified January 28 22:30 EST 2022. Contains 350669 sequences. (Running on oeis4.)