OFFSET
0,2
FORMULA
a(n) = floor(c * 2^prime(n)) for n > 0, where c = 0.91468250985... = 1/2 + A051006.
EXAMPLE
a(7) = 119889 (in base 10) = 11101010001010001 (in base 2).
||| | | | | |
123 5 7 1113 17
MATHEMATICA
a[0] = 1; a[n_] := 2^(Prime[n] - 1) + Sum[2^(Prime[n] - Prime[k]), {k, 1, n}]; Table[a[n], {n, 0, 21}]
PROG
(PARI) a(n) = if (n==0, 1, 2^(prime(n)-1) + sum(k=1, n, 2^(prime(n)-prime(k)))); \\ Michel Marcus, Mar 18 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 18 2020
STATUS
approved