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A014405
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Number of arithmetic progressions of 3 or more positive integers, strictly increasing with sum n.
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2
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0, 0, 0, 0, 0, 1, 0, 0, 2, 1, 0, 3, 0, 1, 5, 1, 0, 6, 0, 2, 7, 2, 0, 8, 2, 2, 9, 3, 0, 13, 0, 2, 11, 3, 4, 15, 0, 3, 13, 6, 0, 18, 0, 4, 20, 4, 0, 19, 2, 8, 18, 5, 0, 23, 6, 6, 20, 5, 0, 30, 0, 5, 25, 6, 7, 29, 0, 6, 24, 15, 0, 32, 0, 6, 34, 7, 4, 34, 0, 14, 31, 7, 0, 39, 9, 7, 31, 9, 0, 49, 5, 9, 33, 8, 10, 42, 0, 12
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,9
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EXAMPLE
| E.g. 15 = 1+2+3+4+5 = 1+5+9 = 2+5+8 = 3+5+7 = 4+5+6.
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PROG
| (PARI) a(n)= t=0; st=0; forstep(s=(n-3)\3, 1, -1, st++; for(c=1, st, m=3; w=m*(s+c); while(w<n, w=w+s+m*c; m++); if(w==n, t++))); t - Rick L. Shepherd (rshepherd2(AT)hotmail.com), Aug 30 2006
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CROSSREFS
| Sequence in context: A200123 A187616 A050464 * A143153 A127448 A128179
Adjacent sequences: A014402 A014403 A014404 * A014406 A014407 A014408
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KEYWORD
| nonn
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AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu)
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