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Search: id:A104290
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| A104290 |
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a = a(n) is such that the a-th prime p(a) is the least prime with digital sum equal to n, or a(n)=0 if no such prime exists. |
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+0
1
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| 0, 1, 2, 6, 3, 0, 4, 7, 0, 8, 10, 0, 19, 17, 0, 22, 24, 0, 46, 77, 0, 95, 109, 0, 168, 290, 0, 303, 430, 0, 669, 887, 0, 2064, 1117, 0, 3245, 4203, 0, 5133, 6057, 0, 7837, 9505, 0, 17984, 33067, 0, 49025, 49098, 0, 63951, 77777, 0, 216751, 216816, 0, 348513
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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a(1)=0 because there is no prime with digital sum equal to 1, a(2)=1 because p(1)=2 is the least prime with digital sum equal to 2, a(3)=2 because p(2)=3 the only prime with digital sum equal to 3, a(3k>3)=0 because there is no prime with digital sum equal to 3 (besides p(2)=3), a(53)=77777 because p(77777)=989999 is the least prime with digital sum (9+8+9+9+9+9) equal to 53. For the first 1,000,000 primes, the maximal digital sum is 62 (for p(658445)=9899999).
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MATHEMATICA
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ta=Table[Plus@@IntegerDigits[Prime[i]], {i, 1000000}]; A104290={0, 1, 2, Table[If[Mod[k, 3]==0, 0, Position[ta, k][[1]]], {k, 4, 54}]}//Flatten
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CROSSREFS
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Adjacent sequences: A104287 A104288 A104289 this_sequence A104291 A104292 A104293
Sequence in context: A005729 A086660 A102068 this_sequence A136759 A056129 A059433
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Feb 28 2005
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