The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A303388 Sequence gives the denominators, in increasing values, of Egyptian fractions such that their alternating sum has the concatenation of these denominators as decimal part. a(1) = 3. 21
 3, 299, 98957, 118885566690, 7993597110943689863079 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Similar to A302932. a(6) > 10^40. - Giovanni Resta, Apr 23 2018 LINKS Eric Weisstein's World of Mathematics, Egyptian fraction Eric Weisstein's World of Mathematics, Trott constants (similar but with continued fractions) EXAMPLE We start from 3 because 1/3 = 0.3333... Then the next integer is 299 because 1/3 - 1/299 = 0.32998885. Next term is 98957 because 1/3 - 1/299 + 1/98957 = 0.3299989571272... and so on. The alternating sum is 0.3 299 98957 118885566690 ... MAPLE with(numtheory): P:=proc(q) local a, b, d, n, t; a:=1/3; b:=1; d:=3; print(d); t:=1; for n from 1 to q do if trunc(evalf(a+(-1)^t/n, 100)*10^(b+ilog10(n)+1))=d*10^(ilog10(n)+1)+n then b:=b+ilog10(n)+1; d:=d*10^(ilog10(n)+1)+n; a:=a+(-1)^t/n; t:=t+1; print(n); fi; od; end: P(10^20); CROSSREFS Cf. A302932, A302933. Sequence in context: A104821 A282195 A334177 * A328044 A119065 A119069 Adjacent sequences:  A303385 A303386 A303387 * A303389 A303390 A303391 KEYWORD nonn,base,more AUTHOR Paolo P. Lava, Apr 23 2018 EXTENSIONS a(4)-a(5) from Giovanni Resta, Apr 23 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 27 12:58 EDT 2022. Contains 354097 sequences. (Running on oeis4.)