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A333176 a(n) = Sum_{k=1..n} (binomial(n,k) mod 2) * prime(k). 1
2, 3, 10, 7, 20, 23, 58, 19, 44, 51, 112, 63, 140, 151, 328, 53, 114, 117, 250, 131, 276, 287, 604, 161, 342, 355, 742, 383, 798, 825, 1720, 131, 270, 273, 566, 289, 596, 607, 1252, 323, 664, 675, 1392, 711, 1458, 1481, 3046, 407, 832, 839, 1718, 875, 1782 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

FORMULA

Sum_{k=1..n} (-1)^A010060(n-k) * (binomial(n,k) mod 2) * a(k) = prime(n).

MATHEMATICA

Table[Sum[Mod[Binomial[n, k], 2] Prime[k], {k, 1, n}], {n, 1, 53}]

PROG

(PARI) a(n) = sum(k=1, n, if (binomial(n, k) % 2, prime(k))); \\ Michel Marcus, Mar 10 2020

CROSSREFS

Cf. A000040, A007443, A007504, A010060, A030015, A050513.

Sequence in context: A336091 A128531 A123167 * A338043 A141670 A278561

Adjacent sequences:  A333173 A333174 A333175 * A333177 A333178 A333179

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Mar 10 2020

STATUS

approved

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Last modified September 17 14:07 EDT 2021. Contains 347478 sequences. (Running on oeis4.)