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A181516 Primes in A011371. 3
3, 7, 11, 19, 23, 31, 41, 47, 53, 67, 71, 73, 79, 89, 97, 101, 109, 113, 127, 131, 137, 149, 173, 181, 191, 193, 197, 229, 239, 263, 271, 277, 281, 293, 311, 337, 349, 353, 359, 367, 383, 389, 397, 401, 421, 431, 439, 449, 461, 463, 467, 479, 487, 491, 499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes p such that 2^p divides some factorial m!, but 2^(p+1) does not divide m!.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

f[n_] := n - DigitCount[n, 2, 1]; s={}; Do[If[PrimeQ[(p = f[n])], AppendTo[s, p]], {n, 1, 510, 2}]; s (* Amiram Eldar, Sep 13 2019 *)

Select[Table[n-DigitCount[n, 2, 1], {n, 0, 600}], PrimeQ]//Union (* Harvey P. Dale, Oct 10 2020 *)

CROSSREFS

Cf. A011371.

Sequence in context: A131426 A080978 A160216 * A285015 A002145 A002052

Adjacent sequences:  A181513 A181514 A181515 * A181517 A181518 A181519

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Oct 26 2010

EXTENSIONS

Comment and definition swapped by R. J. Mathar, Oct 29 2010

STATUS

approved

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Last modified January 25 02:32 EST 2021. Contains 340414 sequences. (Running on oeis4.)