Original entry on oeis.org
3, 33, 315, 26163, 235953, 2125035, 19129689, 172180323, 1549662273, 13947078555, 125524061289, 1129717614483, 10167461718993, 91507165036875, 823564514029689, 7412080712360643, 66708726669526113, 600378540800575995, 5403406869529706889, 48630661832740930803
Offset: 1
A291658
a(n) is the sum of all integers from 5^n to 5^(n+1)-1.
Original entry on oeis.org
10, 290, 7450, 187250, 4686250, 117181250, 2929656250, 73242031250, 1831053906250, 45776363281250, 1144409160156250, 28610229394531250, 715255736816406250, 17881393430175781250, 447034835803222656250, 11175870895324707031250, 279396772384338378906250
Offset: 0
For n=0, the sum is from 1 to 4, so a(0)=10;
for n=1, the sum is from 5 to 24, so a(1)=290, etc.
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a:= unapply(sum(i, i=5^n..5^(n+1)-1), n):
seq(a(n), n=0..20); # Alois P. Heinz, Sep 25 2017
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Vec(10*(1 - x) / ((1 - 5*x)*(1 - 25*x)) + O(x^30)) \\ Colin Barker, Sep 12 2017
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