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A258621 Decimal expansion of sum(1/A030450). 1
2, 2, 5, 6, 9, 4, 7, 4, 5, 8, 5, 2, 6, 5, 9, 7, 9, 5, 5, 4, 6, 2, 7, 3, 6, 7, 2, 4, 4, 4, 2, 3, 4, 2, 2, 1, 0, 5, 5, 9, 2, 3, 6, 5, 0, 8, 8, 9, 3, 6, 9, 5, 9, 5, 3, 3, 4, 6, 0, 0, 4, 9, 6, 0, 9, 2, 6, 7, 5, 4, 9, 2, 8, 1, 7, 5, 2, 2, 0, 0, 6, 7, 7, 6, 1, 4, 8, 9, 6, 2, 1, 3, 3, 1, 7, 7, 7, 7, 7, 7, 2, 8, 5, 6, 4, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..106.

EXAMPLE

2.2569474585265979554627367244423422105592365088936959533....

PROG

(Sage)

def A030450(n) :

   return prod((n-i+1)^(2^i) for i in (1..n))

N(sum(1/A030450(n) for n in (0..9)), digits=106)

(C)

#include <stdio.h>

#include <mpfr.h>

#define dBIT   512

#define dLIST  n, t, u

int main (void) {

mpfr_t dLIST;

mpfr_rnd_t trnd;

unsigned int i;

trnd = MPFR_RNDU;

mpfr_inits2 (dBIT, dLIST, (mpfr_ptr) 0);

mpfr_set_d (n, 1.0, trnd);

mpfr_set_d (t, 1.0, trnd);

for (i = 1; i <= 9; i++) {

    mpfr_mul_ui (t, t, i, trnd);

    mpfr_mul (t, t, t, trnd);

    mpfr_set_d (u, 1.0, trnd);

    mpfr_div (u, u, t, trnd);

    mpfr_add (n, n, u, trnd);

}

mpfr_printf ("%.106Rg", n);

mpfr_clears (dLIST, (mpfr_ptr) 0);

return 0;

}

CROSSREFS

Cf. A030450.

Sequence in context: A239262 A288496 A292726 * A258619 A118807 A240309

Adjacent sequences:  A258618 A258619 A258620 * A258622 A258623 A258624

KEYWORD

nonn,cons

AUTHOR

Jani Melik, Jun 06 2015

STATUS

approved

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Last modified January 16 06:41 EST 2021. Contains 340204 sequences. (Running on oeis4.)