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Search: id:A134803
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| A134803 |
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Numbers n such that the sum of all numbers of the same parity <= n is equal to the sum of numbers of the opposite parity from n+1 to n+m, where m is odd and > 1. |
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+0
2
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OFFSET
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1,1
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EXAMPLE
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3 -> 1+3 = 4 = 4
8 -> 2+4+6+8 = 20 = 9+11
119 -> 1+3+5+...+119 = 3600 = 120+122+...+168
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MAPLE
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P:=proc(n) local a, k, i, s1, s2; for i from 1 by 1 to n do if 2*trunc(i/2)=i then s1:=sum('2*k', 'k'=1..(i/2)); else s1:=sum('2*k-1', 'k'=1..(i+1)/2); fi; a:=1; s2:=i+1; while s1>s2 do a:=a+2; s2:=s2+i+a; od; if s1=s2 then lprint(i, s1); fi; od; end: P(10000);
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CROSSREFS
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Cf. A001109, A084068, A089895.
Sequence in context: A066619 A028504 A123279 this_sequence A030063 A051047 A036504
Adjacent sequences: A134800 A134801 A134802 this_sequence A134804 A134805 A134806
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KEYWORD
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easy,nonn
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AUTHOR
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Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jan 28 2008
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