A136040 Classes of the phi iteration for which the smallest number is prime.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 16, 17, 19, 21, 22, 25, 26, 29, 31, 41, 49, 51, 52, 55, 58, 59, 60, 63, 65, 66, 67, 69, 71, 74, 77, 79, 81, 82, 87, 89, 108, 109, 113, 114, 116, 119, 122, 124, 127, 129, 130, 136, 137, 142, 143, 145, 147, 148, 151, 154, 158, 159, 161, 162, 163

Offset

1,2

Comments

Rows of A058812 which begin with a prime. The actual primes are in A092873, which is A007755(n+2) for the n in this sequence.

Links

T. D. Noe, Table of n, a(n) for n=1..288

T. D. Noe, Primes in classes of the iterated totient function, JIS 11 (2008) 08.1.2

Harold Shapiro, An arithmetic function arising from the phi function, Amer. Math. Monthly, Vol. 50, No. 1 (1943), 18-30.

Crossrefs

Sequence in context: A108155 A134932 A134933 * A306014 A271838 A194846

Adjacent sequences: A136037 A136038 A136039 * A136041 A136042 A136043

Keyword

nonn

Author

T. D. Noe, Dec 12 2007

Extensions

Added 63 and 159. - T. D. Noe, Nov 18 2008

Status

approved