A323362 a(n) is the smallest k such that the sum of the first k primes is >= 10^n.

1, 3, 9, 25, 68, 191, 547, 1593, 4692, 13941, 41710, 125494, 379324, 1150976, 3503793, 10695889, 32729282, 100361004, 308313172, 948694980, 2923428287, 9020381557, 27865631947, 86174159206, 266752375679, 826469488966, 2562720437746

Offset

0,2

Comments

The final primes in the sums are 2, 5, 23, 97, 337, 1153, 3943, 13441, 45197, 151091, 502259, 1662377, 5477083, 17993477, 58954411, 192682537, 628420129, 2045812157, 6649205951, 21579536893, 69943284097, 226431374423, 732253012171, 2365707119579, 7636102747789, 24627776205037, 79368662592367, 255604186937213, 822628809813047, ..., .

Links

Table of n, a(n) for n=0..26.

Mathematica

p = 2; k = s = 0; lst = {}; Do[ While[s < 10^n, s = s + p; p = NextPrime@ p; k++]; AppendTo[lst, k; Print@ k], {n, 20}]; lst

Crossrefs

Cf. A007504, A323360, A323361.

Sequence in context: A291019 A236570 A338726 * A201533 A000242 A077846

Adjacent sequences: A323359 A323360 A323361 * A323363 A323364 A323365

Keyword

nonn

Author

Robert G. Wilson v, Jan 12 2019

Status

approved