This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091932 Primes that remain prime when their leading digit in binary representation is replaced by 0. 8
 7, 11, 13, 19, 23, 29, 37, 43, 61, 67, 71, 83, 101, 107, 131, 139, 151, 157, 181, 199, 211, 229, 241, 263, 269, 293, 317, 353, 359, 383, 419, 449, 467, 479, 523, 541, 571, 601, 613, 619, 643, 661, 691, 709, 739, 751, 769, 823, 829, 859, 991, 1021, 1031 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A053645(a(n)) is prime. Primes p such that p - 2^floor(log2(p)) is prime - T. D. Noe, Apr 08 2011 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 FORMULA A118953(A049084(a(n))) = 1; subsequence of A065380. - Reinhard Zumkeller, May 07 2006 EXAMPLE A000040(12)=37 --> '100101' --> '[1]00101' --> '[0]00101' --> '101' --> 5, therefore 37 is a term. MATHEMATICA Select[Prime[Range[100]], PrimeQ[# - 2^Floor[Log[2, #]]] &] (* T. D. Noe, Apr 08 2011 *) Select[Prime[Range[200]], PrimeQ[FromDigits[Rest[ IntegerDigits[ #, 2]], 2]]&] (* Harvey P. Dale, Apr 08 2016 *) CROSSREFS Cf. A091931. Cf. A118958. Sequence in context: A152469 A115558 A067466 * A165349 A160024 A063911 Adjacent sequences:  A091929 A091930 A091931 * A091933 A091934 A091935 KEYWORD nonn AUTHOR Reinhard Zumkeller, Feb 14 2004 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.