A247234 First occurrence of 2*n in A035096.

2, 4, 7, 20, 8, 17, 39, 134, 45, 206, 149, 49, 66, 321, 88, 98, 637, 382, 259, 284, 820, 302, 310, 1102, 1597, 3763, 1140, 3432, 741, 532, 4751, 856, 4855, 3446, 2130, 3256, 3407, 694, 2250, 4878, 5588, 13199, 15211, 9040, 7426, 11126, 5931, 11699, 22463, 26223, 37546, 37602, 42795, 32776

Offset: 1

Author

Robert G. Wilson v, Dec 28 2014

Keywords

• nonn

Examples

			a(1) = 2 since the first appearance of 2 occurs at A035096(2);
a(3) = 7 since the first appearance of 6 occurs at A035096(7).
		

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..276

Crossrefs

Cf. A035096.

Programs

Mathematica

f[n_] := Block[{p = Prime@ n}, q = 1 + 2p; While[ !PrimeQ@ q, q += 2p]; (q - 1)/p]; f[1] = 1; t = Table[0, {1000}]; k = 2; While[k < 10^5, a = f@ k /2; If[ t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++]; t