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A091736 Numerators of the coefficients of a power series for the canonical half-exponential function. 2
1, -1, 1, -1, 1, -25, 7, -11, 5, -4001, 107, -6721, 187, -2048761, 44143, -3951137, 43663, -2300524417, 2591885, -107137061, 5512427, -4571262603161, 81607991, -10073849103649, 136193843 (list; graph; refs; listen; history; internal format)
OFFSET

0,6

COMMENTS

I feel that this is an important sequence, but its definition is not clear to me. As an interim measure, the link gives some additional comments that the author sent me.

LINKS

Enrico T. Federighi, Notes on this sequence

Mathoverflow, Does the exponential function have a square root?

Mathoverflow, f(f(x))=exp(x)-1 and other...

FORMULA

Starting with (1-x+x^2-x^3-x^4) If x=sqrt(ln(1.1)) this series would solve for f(-1/2)=.7640669761635259978040594 ... where 1.1^f(x)=f(x+1) and f(-1)=0.

Since the ratio of the absolute value of terms approaches sqrt(2.718281828...) the series converges whenever x<1/(sqrt( 2.718281828...).

CROSSREFS

Cf. A091737.

Sequence in context: A040609 A040607 A040606 * A126837 A080203 A040605

Adjacent sequences:  A091733 A091734 A091735 * A091737 A091738 A091739

KEYWORD

sign,frac,uned,obsc

AUTHOR

Enrico T. Federighi (rico125162(AT)aol.com), Feb 02 2004

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Last modified February 15 07:19 EST 2012. Contains 205703 sequences.