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 A138823 Divisors of 248 (the 3rd perfect number divided by 2), written in base 2. 0
 1, 10, 100, 1000, 11111, 111110, 1111100, 11111000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 248 is the number of dimensions of E_8. a(n) has n digits. LINKS EXAMPLE The structure of divisors of 248 (see A018355) .................................................................. n ............ Divisor . Formula ....... Divisor written in base 2 .................................................................. 1) ................. 1 = 2^0 ........... 1 2) ................. 2 = 2^1 ........... 10 3) ................. 4 = 2^2 ........... 100 4) A134708(3) = .... 8 = 2^3 ........... 1000 5) A000668(3) = ... 31 = 2^5 - 2^0 ..... 11111 6) ................ 62 = 2^6 - 2^1 ..... 111110 7) ............... 124 = 2^7 - 2^2 ..... 1111100 8) A133028(3) = .. 248 = 2^8 - 2^3 ..... 11111000 MATHEMATICA FromDigits[IntegerDigits[#, 2]]&/@Divisors[248] (* Harvey P. Dale, Apr 01 2017 *) PROG (PARI) divisors(248) \\ Charles R Greathouse IV, Sep 06 2016 CROSSREFS Perfect number divided by 2: A133028. Cf. A000043, A000396, A000668, A018355, A090748, A134708, A135653. Sequence in context: A290857 A290657 A286864 * A145442 A267456 A282580 Adjacent sequences:  A138820 A138821 A138822 * A138824 A138825 A138826 KEYWORD easy,fini,full,nonn,less AUTHOR Omar E. Pol, Mar 31 2008, corrected Apr 03 2008 STATUS approved

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Last modified February 16 15:59 EST 2020. Contains 331961 sequences. (Running on oeis4.)