A215609 Smallest prime p congruent to 1 modulo prime(10^n).

3, 59, 9739, 63353, 209459, 15596509, 154858631, 1794246731, 4076149487, 45603526979, 11092303227413, 93864728285579, 1319833868136653, 11656098322067917, 27803086068196217, 1781976386163140977, 32382366940106296979, 100447117955224696057, 707388643757314709297

Offset

0,1

Links

Amiram Eldar, Table of n, a(n) for n = 0..24

Formula

a(n) = A035095(10^n).

Example

a(0) = 3 because p = prime(1) = 2, 3 = 1+p.
a(1) = 59 because p = prime(10) = 29, 59 = 1+2*p.
a(2) = 9739 because p = prime(10) = 29, 59 = 1+18*p.

Mathematica

a[n_]:=(If[n<2, 3, p=Prime[n]; r=2p+1; While[!PrimeQ[r], r=r+2p]; r]); Table[a[10^n], {n, 0, 12}]

Crossrefs

Cf. A035095, A006988.

Sequence in context: A062629 A184953 A185153 * A360837 A201184 A046024

Adjacent sequences: A215606 A215607 A215608 * A215610 A215611 A215612

Keyword

nonn,changed

Author

Zak Seidov, Aug 17 2012

Extensions

a(13)-a(18) from Amiram Eldar, Apr 30 2024

Status

approved