A061108 Compute Euler totient function for the prime(n+1)-prime(n)-1 composite numbers between two consecutive primes; choose the largest.

2, 2, 6, 4, 8, 6, 12, 20, 8, 24, 24, 12, 24, 42, 40, 16, 48, 44, 24, 60, 54, 64, 72, 60, 32, 52, 36, 72, 110, 84, 108, 44, 120, 40, 120, 132, 82, 156, 120, 48, 160, 64, 96, 60, 180, 192, 120, 72, 120, 184, 64, 216, 220, 216, 208, 72, 200, 180, 92, 272, 264, 204, 96

Offset

2,1

Links

Harry J. Smith, Table of n, a(n) for n = 2..1000

Formula

a(n) = Max{phi(c); prime(n) < c < prime(n+1)}.

Prog

(PARI) { n=1; q=3; forprime (p=5, prime(1003), a=0; for (i=q + 1, p - 1, a=max(eulerphi(i), a)); q=p; write("b061108.txt", n++, " ", a) ) } \\ Harry J. Smith, Jul 18 2009]

Crossrefs

Cf. A000010, A061106.

Sequence in context: A174222 A071059 A256468 * A284918 A053213 A292258

Adjacent sequences: A061105 A061106 A061107 * A061109 A061110 A061111

Keyword

nonn

Author

Labos Elemer, May 29 2001

Extensions

Offset corrected by Michel Marcus, Mar 21 2018

Status

approved