A249339 Positions of ones in A249336; positions of zeros in A249338.

1, 2, 4, 6, 14, 21, 40, 51, 71, 81, 98, 132, 143, 194, 241, 258, 297, 323, 380, 398, 436, 479, 491, 543, 570, 630, 737, 759, 765, 829, 836, 873, 1068, 1101, 1210, 1215, 1370, 1415, 1469, 1515, 1550, 1607, 1682, 1701, 1854, 1872, 1904, 1932, 2117, 2245, 2294, 2304, 2344

Offset: 1

Author

Antti Karttunen, Oct 26 2014

Keywords

• nonn

Links

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

Crossrefs

Cf. A249336, A249338, A249340, A249341.

Programs

PARI

allocatemem(234567890);
A049084(n) = if(isprime(n), primepi(n), 0); \\ This function from Charles R Greathouse IV
A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i,2] * A049084(f[i,1]))); }
A249339_write_bfile(up_to_n) = { my(counts, n, k, a_k); counts = vector(min((2^24)-8,up_to_n^2)); n = 0; k = 0; a_k = 1; while(n < up_to_n, k++; if((0 == A056239(a_k)), n++; write("b249339.txt", n, " ", k)); counts[1+A056239(a_k)]++; a_k = counts[1+A056239(a_k)]); };
A249339_write_bfile(10000);

Scheme

;; With Antti Karttunen's IntSeq-library, two alternative definitions.
(define A249339 (MATCHING-POS 1 1 (lambda (n) (= 1 (A249336 n)))))
(define A249339 (ZERO-POS 1 1 A249338))

Formula

For n >= 2, a(n) = 1 + A249340(n-1).