A185107 a(n) is the first digit of prime(n) minus the sum of the other digits.

2, 3, 5, 7, 0, -2, -6, -8, -1, -7, 2, -4, 3, 1, -3, 2, -4, 5, -1, 6, 4, -2, 5, -1, 2, 0, -2, -6, -8, -3, -8, -3, -9, -11, -12, -5, -11, -8, -12, -9, -15, -8, -9, -11, -15, -17, 0, -3, -7, -9, -4, -10, -3, -4, -10, -7, -13

Offset: 1

Author

Dario Piazzalunga, Dec 27 2012

Keywords

• sign
• base
• less

Comments

Absolute terms are the same as A042939.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A042939, A007605.

Programs

Mathematica

Table[With[{id=IntegerDigits[Prime[n]]},id[[1]]-Total[Rest[id]]],{n,60}] (* Harvey P. Dale, Oct 04 2024 *)

PARI

a(n) = {digs = digits(prime(n)); digs[1] - sum(i=2, #digs, digs[i]);} \\ Michel Marcus, Aug 30 2013

Extensions

a(38) corrected by Michel Marcus, Jun 14 2022