A249340 Position of the first occurrence of n-th noncomposite number, A008578(n), in A249336; positions of records in A249338.

1, 3, 5, 13, 20, 39, 50, 70, 80, 97, 131, 142, 193, 240, 257, 296, 322, 379, 397, 435, 478, 490, 542, 569, 629, 736, 758, 764, 828, 835, 872, 1067, 1100, 1209, 1214, 1369, 1414, 1468, 1514, 1549, 1606, 1681, 1700, 1853, 1871, 1903, 1931, 2116, 2244, 2293, 2303, 2343

Offset

1,2

Links

Table of n, a(n) for n=1..52.

Formula

a(n) = A249339(n+1) - 1.

Other identities. For all n >= 1:

A249336(a(n)) = A008578(n).

A249338(a(n)) = n-1.

Prog

(Scheme, with Antti Karttunen's IntSeq-library, two alternative definitions)
(define A249340 (MATCHING-POS 1 1 (lambda (n) (and (= 1 (A249336 (+ 1 n))) (or (= 1 (A249336 n)) (prime? (A249336 n)))))))
(define A249340 (RECORD-POS 1 1 A249338))

Crossrefs

Cf. A249336, A249338, A249339.

Sequence in context: A106915 A112928 A106916 * A034484 A290441 A222752

Adjacent sequences: A249337 A249338 A249339 * A249341 A249342 A249343

Keyword

nonn

Author

Antti Karttunen, Oct 26 2014

Status

approved