A319525 Completely multiplicative with a(prime(k)) = prime(2*k - 1) (where prime(k) denotes the k-th prime).

1, 2, 5, 4, 11, 10, 17, 8, 25, 22, 23, 20, 31, 34, 55, 16, 41, 50, 47, 44, 85, 46, 59, 40, 121, 62, 125, 68, 67, 110, 73, 32, 115, 82, 187, 100, 83, 94, 155, 88, 97, 170, 103, 92, 275, 118, 109, 80, 289, 242, 205, 124, 127, 250, 253, 136, 235, 134, 137, 220

Offset

1,2

Comments

This sequence is a permutation of A066208.

See A297002 for a similar sequence.

Links

Table of n, a(n) for n=1..60.

Formula

a(n) = A064989(A297002(n)).

a(n) >= n with equality iff n is a power of 2 (A000079).

Prog

(PARI) a(n) = my (f=factor(n)); prod(i=1, #f~, prime(2*primepi(f[i, 1]) - 1)^f[i, 2])

Crossrefs

Cf. A000079, A066208, A297002.

Sequence in context: A072403 A010078 A074639 * A357983 A338459 A343035

Adjacent sequences: A319522 A319523 A319524 * A319526 A319527 A319528

Keyword

nonn,mult

Author

Rémy Sigrist, Sep 22 2018

Status

approved