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A161180
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Sum of primes between n^2 and n^2+n, n^2+n and (n+1)^2. The only intervals for which n^2+n is prime are [1,2], [2,4] and the endpoint 2 is included in the sum. One might have written 0,3,5,7,..., etc.
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1
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2, 5, 5, 7, 11, 13, 36, 23, 29, 31, 78, 90, 53, 120, 138, 152, 172, 97, 420, 113, 258, 276, 300, 487, 533, 384, 396, 434, 928, 492, 1060, 841, 293, 1248, 668, 1408, 1119, 1169, 1229, 1724, 1810, 1409, 1980, 1553, 1088, 2260, 2356, 3057, 2562, 2646, 2752, 2155
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| On [1,2] the sum of primes is 2. For [2,4] the sum is 5. [4,6]: 5, [6,9]: 7, [9,12]: 11, [12,16]: 13, [16,20]: 17+19 = 36.
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MAPLE
| A161180 := proc(n) a := 0 ; if type(n, 'odd') then nloc := (n+1)/2 ; for p from nloc^2 to nloc^2+nloc do if isprime(p) then a := a+p ; end if; end do: else nloc := n/2 ; for p from nloc^2+nloc to (nloc+1)^2 do if isprime(p) then a := a+p ; end if; end do: end if; a; end proc: seq(A161180(n), n=1..120) ; [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2010]
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CROSSREFS
| Cf. A160907
Sequence in context: A023850 A175649 A142353 * A101858 A165917 A165898
Adjacent sequences: A161177 A161178 A161179 * A161181 A161182 A161183
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KEYWORD
| easy,nonn
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AUTHOR
| Daniel Tisdale (daniel6874(AT)gmail.com), Jun 05 2009
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EXTENSIONS
| Corrected (128 replaced by 138) and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 31 2010
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