A042939 Absolute values between digits of primes.

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, 6, 12, 7, 9, 10, 4, 1, 1, 5, 1, 7, 8, 10, 5, 11, 10, 7, 13, 8, 14, 13, 3, 5, 6, 1, 0, 2, 8, 3, 9, 8, 3, 5, 9, 12, 11, 6

Offset: 1

Author

Felice Russo

Keywords

• base
• nonn

Comments

a(n) = absolute difference between the first digit of prime(n) and the sum of the other digits of prime(n). [Harvey P. Dale, Mar 11 2012]

Links

• James Spahlinger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A041000, A040164, A000040.

Cf. A007605.

Programs

Haskell

a042939 = a040997 . a000040
-- Reinhard Zumkeller, Oct 10 2012

Mathematica

ddp[n_]:=Module[{idn=IntegerDigits[n]},Abs[First[idn]-Total[Rest[idn]]]]; ddp/@Prime[Range[100]] (* Harvey P. Dale, Mar 11 2012 *)

Formula

If decimal expansion of n-th prime is x1 x2 x3......xk then a(n)=|x1-x2-x3.......-xk|

a(n) = A040997(A000040(n)). - Reinhard Zumkeller, Oct 10 2012