A364618 - OEIS

A364618

Decimal expansion of Sum_{k>=0} erfc(k), where erfc(x) is the complementary error function.

1, 1, 6, 1, 9, 9, 9, 0, 4, 7, 9, 4, 7, 1, 2, 6, 3, 6, 3, 5, 3, 2, 3, 0, 8, 3, 2, 2, 4, 5, 5, 7, 9, 7, 1, 7, 1, 1, 6, 6, 3, 4, 3, 5, 0, 6, 2, 2, 5, 8, 6, 8, 0, 3, 1, 2, 1, 6, 8, 2, 6, 3, 3, 2, 4, 1, 5, 9, 4, 1, 7, 5, 5, 0, 4, 9, 4, 0, 0, 2, 3, 8, 6, 4, 7, 8, 1, 3, 2, 8, 3, 6, 2, 6, 2, 8, 9, 3, 3, 5, 1, 8, 4, 4, 7

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OFFSET

1,3

LINKS

Table of n, a(n) for n=1..105.

Tyma Gaidash, John Barber, and Steven Clark, How to evaluate Sum_{x=0..oo} erfc(x) = 1.1619990479471263635323...?, Mathematics StackExchange, 2021.

Eric Weisstein's World of Mathematics, Dawson's Integral.

Eric Weisstein's World of Mathematics, Erfc.

Wikipedia, Dawson function.

Wikipedia, Error function.

FORMULA

Equals 1 + (2/Pi) * Integral_{x>=1} floor(x) * exp(-x^2) dx.