A249735 Odd bisection of A003961: Replace in 2n-1 each prime factor p(k) with prime p(k+1).

1, 5, 7, 11, 25, 13, 17, 35, 19, 23, 55, 29, 49, 125, 31, 37, 65, 77, 41, 85, 43, 47, 175, 53, 121, 95, 59, 91, 115, 61, 67, 275, 119, 71, 145, 73, 79, 245, 143, 83, 625, 89, 133, 155, 97, 187, 185, 161, 101, 325, 103, 107, 385, 109, 113, 205, 127, 203, 425, 209, 169, 215, 343, 131, 235, 137, 253, 875, 139, 149, 265, 221, 217, 605, 151

Offset

1,2

Comments

This has the same terms as A007310 (Numbers congruent to 1 or 5 mod 6), but in different order. Apart from 1, they are the numbers that occur below the first two rows of arrays like A246278 and A083221 (A083140).

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Formula

a(n) = A003961(2n - 1).

a(n) = A007310(A249746(n)). [Permutation of A007310, Numbers congruent to 1 or 5 mod 6.]

Other identities. For all n >= 1:

A007310(n) = a(A249745(n)).

A246277(5*a(A048673(n))) = n.

A246277(5*a(n)) = A064216(n).

Prog

(Scheme) (define (A249735 n) (A003961 (+ n n -1)))

Crossrefs

Cf. A249734 (the other bisection of A003961).

Cf. also A007310 (A038179), A249746.

Sequence in context: A075705 A340308 A339096 * A218394 A067289 A036491

Adjacent sequences: A249732 A249733 A249734 * A249736 A249737 A249738

Keyword

nonn

Author

Antti Karttunen, Nov 23 2014

Status

approved