A390151 Decimal expansion of the absolute value of the sum of gamma function for all negative half integers.

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

Offset

1,2

Links

Table of n, a(n) for n=1..87.

Formula

Equals -Sum_{n>=0} Gamma(-n-1/2).

Equals (Pi/e)*erfi(1).

Example

1.907442188241755232...

Mathematica

RealDigits[Pi*Erfi[1]/E, 10, 120][[1]]

Prog

(PARI) Pi * exp(-1) * imag(1 - erfc(I)) \\ Amiram Eldar, Nov 24 2025

Crossrefs

Cf. A000796, A001113, A099288, A351400.

Sequence in context: A388199 A384283 A372830 * A385960 A381653 A388361

Adjacent sequences: A390148 A390149 A390150 * A390152 A390153 A390154

Keyword

nonn,cons

Author

Jwalin Bhatt, Nov 24 2025

Status

approved