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Search: id:A062337
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| A062337 |
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Primes whose sum of digits is 7. |
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+0
4
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| 7, 43, 61, 151, 223, 241, 313, 331, 421, 601, 1033, 1051, 1123, 1213, 1231, 1303, 1321, 2113, 2131, 2203, 2221, 2311, 3121, 3301, 4003, 4021, 4111, 4201, 5011, 5101, 10141, 10303, 10321, 10501, 11113, 11131, 11311, 12211, 12301, 13003, 14011
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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There are O((log n)^6) members of this sequence below n.
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LINKS
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Charles R Greathouse IV, Table of n, a(n) for n=1..10000
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EXAMPLE
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601 is a prime with sum of the digits =7, hence belongs to the sequence.
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MATHEMATICA
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Select[Prime[Range[3000]], Plus @@ IntegerDigits[ # ] == 7 &] (Zak Seidov (zakseidov(AT)yahoo.com), Feb 17 2005)
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PROGRAM
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(PARI) A062337(lim)={my(pow=ceil(log(floor(lim)-.5)/log(10)), n); print("Checking for members of A062337 up to 10^"pow); for(a=0, pow-1, for(b=0, a, for(c=0, b, for(d=0, c, for(e=0, d, for(f=0, e, n=10^a+10^b+10^c+10^d+10^e+10^f+1; if(isprime(n), print1(n", "))))))))};
(PARI) SumD(x)= { s=0; while (x>9, s+=x-10*(x\10); x\=10); return(s + x) } { default(primelimit, 2*10^8); n=0; forprime (p=2, 2*10^8, if (SumD(p) == 7, write("b062337.txt", n++, " ", p); if (n==500, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 05 2009]
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CROSSREFS
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Subsequence of A062336. See also A000579.
Sequence in context: A062336 A085704 A061241 this_sequence A118703 A139832 A139848
Adjacent sequences: A062334 A062335 A062336 this_sequence A062338 A062339 A062340
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KEYWORD
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nonn,base,easy
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jun 21 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Jul 06 2001
Comments and program by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Sep 11 2009
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