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A136135 Sum of squares until integer log : sopfr(n). Or also, s(s+1)(2s+1)/6 where s=sopfr(n). 0
0, 5, 14, 30, 55, 55, 140, 91, 91, 140, 506, 140, 819, 285, 204, 204, 1785, 204, 2470, 285, 385, 819, 4324, 285, 385, 1240, 285, 506, 8555, 385, 10416, 385, 1015, 2470, 650, 385, 17575, 3311, 1496, 506, 23821, 650, 27434, 1240, 506, 5525, 35720, 506, 1015 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Sequence A074374 is similar, based on the triangular numbers, giving s(s+1)/2 with s=sopfr(n). Here it is based on the square pyramidal numbers, giving s(s+1)(2s+1)/6 with s=sopfr(n).
LINKS
MATHEMATICA
sopfr = Function[x, Plus @@ Map[Times @@ # &, FactorInteger[x]]]; Map[ #(# + 1)(2# + 1)/6 &, sopfr /@ Range[130]]
CROSSREFS
Sequence in context: A161698 A049791 A053461 * A231673 A211653 A096893
KEYWORD
nonn
AUTHOR
Carlos Alves, Dec 16 2007
STATUS
approved

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Last modified June 21 19:43 EDT 2024. Contains 373558 sequences. (Running on oeis4.)