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A289361
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Least sum s of three consecutive primes such that s is a multiple of the n-th prime.
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1
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10, 15, 10, 49, 121, 143, 187, 551, 23, 319, 31, 407, 41, 301, 235, 159, 59, 1891, 1943, 71, 803, 395, 83, 2759, 97, 1717, 3193, 749, 109, 565, 3175, 131, 2329, 1807, 7301, 6493, 471, 1793, 1169, 173, 1611, 5611, 2101, 3281, 985, 199, 211, 223, 1135, 4351, 5359, 11233, 2651
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OFFSET
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1,1
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COMMENTS
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Are all terms distinct? Is a(1)=a(3)=10 the only case of equality?
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LINKS
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EXAMPLE
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MATHEMATICA
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Table[Function[p, k = 1; While[! Divisible[Set[s, Total@ Prime@ Range[k, k + 2]], p], k++]; s]@ Prime@ n, {n, 53}] (* or *)
s = Total /@ Partition[Prime@ Range[10^4], 3, 1]; Table[SelectFirst[s, Divisible[#, Prime@ n] &], {n, 53}] (* Michael De Vlieger, Jul 04 2017 *)
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PROG
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(PARI) a(n)=p = 2; q = 3; pn = prime(n); forprime(r=5, , if (((s=p+q+r) % pn) == 0, return (s)); p = q; q = r; ); \\ Michel Marcus, Jul 04 2017
(PARI) isA034961(n)=my(p=precprime(n\3), q=nextprime(n\3+1), r=n-p-q); if(r>q, r==nextprime(q+2), r==precprime(p-1) && r)
a(n, p=prime(n))=if(p==5, return(10)); my(k=1); while(!isA034961(p*k), k+=2); p*k \\ Charles R Greathouse IV, Jul 05 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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