A380192 Sum mod(10) of digits of n-th prime.

2, 3, 5, 7, 2, 4, 8, 0, 5, 1, 4, 0, 5, 7, 1, 8, 4, 7, 3, 8, 0, 6, 1, 7, 6, 2, 4, 8, 0, 5, 0, 5, 1, 3, 4, 7, 3, 0, 4, 1, 7, 0, 1, 3, 7, 9, 4, 7, 1, 3, 8, 4, 7, 8, 4, 1, 7, 0, 6, 1, 3, 4, 0, 5, 7, 1, 7, 3, 4, 6, 1, 7, 6, 3, 9, 4, 0, 9, 5, 3, 4, 7, 8, 0, 6, 1, 7, 6, 1, 3, 7, 0, 9

Offset: 1

Author

Enrique Navarrete, Jan 15 2025

Keywords

• nonn
• base

Comments

All remainders 0,...,9 occur in this sequence.

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000
• Enrique Navarrete, Distributions of Sums of Digits of Primes

Crossrefs

Cf. A007605, A010879, A053837, A158293.

Programs

Mathematica

Mod[DigitSum[Prime[Range[100]]], 10] (* Paolo Xausa, Feb 06 2025 *)

PARI

a(n) = sumdigits(prime(n)) % 10; \\ Michel Marcus, Jan 16 2025

Formula

a(n) = A010879(A007605(n)).