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 A077721 Primes which can be expressed as sum of distinct powers of 7. 10
 7, 2801, 17207, 19559, 120401, 134513, 134807, 137201, 840743, 842759, 842801, 941249, 943601, 958007, 958049, 958343, 960793, 5782001, 5784409, 5899307, 5899601, 5899657, 5901659, 6591089, 6607903, 6706393, 6708787, 6722801, 6722857, 6723193 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes whose base 7 representation contains only zeros and 1's. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE pos := 0:for i from 1 to 4000 do b := convert(i, base, 2); s := sum(b[j]*7^(j-1), j=1..nops(b)): if(isprime(s)) then pos := pos+1:a[pos] := s:fi: od:seq(a[j], j=1..pos); MATHEMATICA Select[Prime[Range[10^6]], Max[IntegerDigits[#, 7]]<=1 &] (* Vincenzo Librandi, Sep 07 2018 *) CROSSREFS Cf. A020449, A000695, A033044, A077717, A077718, A077719, A077720, A077722, A077723. Sequence in context: A234621 A195680 A203587 * A235464 A297029 A242851 Adjacent sequences: A077718 A077719 A077720 * A077722 A077723 A077724 KEYWORD nonn AUTHOR Amarnath Murthy, Nov 19 2002 EXTENSIONS More terms from Sascha Kurz, Jan 03 2003 STATUS approved

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Last modified March 30 02:54 EDT 2023. Contains 361603 sequences. (Running on oeis4.)