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A083175
Row sums in A083175.
4
2, 12, 30, 84, 165, 312, 476, 760, 1035, 1740, 2046, 3108, 3731, 4816, 5640, 7632, 9027, 10980, 12730, 15620, 16863, 20856, 22908, 27768, 31525, 36764, 38934, 44940, 47415, 54240, 62992, 71264, 76857, 85068, 93870, 103284, 110371, 123880, 130260
OFFSET
1,1
COMMENTS
If p is a prime then a(p) = prime(p)*T(p), where T(p) = the p-th triangular number.
PROG
(PARI) for(i=1, 120, p=prime(i); s=p*((i-1)*(i))/2; t=sum(k=1, i-1, p*k); k=i; while(denominator((s+k*p)/i)>1, k++); t+=k*p; print1(t, ", ")) (Herrgesell)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Apr 26 2003
EXTENSIONS
More terms from Lambert Herrgesell (zero815(AT)googlemail.com), Dec 30 2005
STATUS
approved