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 A066527 Triangular numbers that for some k are also the sum of the first k primes. 5
 10, 28, 133386, 4218060, 54047322253, 14756071005948636, 600605016143706003, 41181981873797476176, 240580227206205322973571, 1350027226921161196478736 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) = A000217(i) = A007504(j) for appropriate i, j. These are the 4, 7, 516, 2904, 328777, ... -th triangular numbers and are the sums of the first 3, 5, 217, 1065, 93448, ... prime numbers respectively. a(7) is the sum of the first 240439822 primes. a(8) is the sum of the first 1894541497 primes. - Donovan Johnson, Nov 24 2008 a(9) is the sum of the first 132563927578 primes. a(10) is the sum of the first 309101198255 primes. a(11) > 6640510710493148698166596 (sum of first pi(2*10^13) primes). - Donovan Johnson, Aug 23 2010 LINKS EXAMPLE a(2) = 28, as A000217(7) = 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28 = 2 + 3 + 5 + 7 + 11 = A007504(5). MAPLE a066527(m) = local(d, ds, p, ps); d=1; ds=1; p=2; ps=2; while(ds

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Last modified May 30 05:35 EDT 2020. Contains 334712 sequences. (Running on oeis4.)