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A124899 Sierpinski quotient ((2n-1)^(2n-1) + 1)/(2n) = A014566(2n-1)/(2n). 2
1, 7, 521, 102943, 38742049, 23775972551, 21633936185161, 27368368148803711, 45957792327018709121, 98920982783015679456199, 265572137199362841880960201, 870019499993663001431459704607 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

2n divides Sierpinski number A014566(2n-1). 2^n divides A014566(2^n-1). A014566[2^n - 1] / 2^n = A081216[2^n - 1] = A122000[n] = {1, 7, 102943, 27368368148803711, 533411691585101123706582594658103586126397951, ...}. p+1 divides A014566(p) for prime p. A014566(p)/(p+1) = A056852[n] = {7, 521, 102943, 23775972551, 21633936185161, ...}. Primes in a(n) are {7, 521, 45957792327018709121}.

LINKS

Eric Weisstein, Link to a section of The World of Mathematics. Sierpinski Numbers of the First Kind.

FORMULA

a(n) = ((2n-1)^(2n-1) + 1)/(2n) = A014566(2n-1)/(2n).

MATHEMATICA

Table[((2n-1)^(2n-1)+1)/(2n), {n, 1, 20}]

CROSSREFS

Cf. A014566 - Sierpinski numbers of the first kind: n^n + 1. Cf. A081216, A122000, A056852.

Sequence in context: A203472 A080975 A003396 * A056852 A126196 A093169

Adjacent sequences:  A124896 A124897 A124898 * A124900 A124901 A124902

KEYWORD

nonn

AUTHOR

Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 12 2006

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.