A129142 Start with the empty sequence and append in step k the consecutive numbers 2^k-1 to 2^k+k-2.

1, 3, 4, 7, 8, 9, 15, 16, 17, 18, 31, 32, 33, 34, 35, 63, 64, 65, 66, 67, 68, 127, 128, 129, 130, 131, 132, 133, 255, 256, 257, 258, 259, 260, 261, 262, 511, 512, 513, 514, 515, 516, 517, 518, 519, 1023, 1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 2047

Offset

1,2

Comments

Inspired by A127330.

Links

Table of n, a(n) for n=1..56.

Example

In step 4 the numbers 2^4-1 to 2^4+4-2 are appended: 15, 16, 17, 18.

Prog

(Magma) &cat[ [2^k-1..2^k+k-2]: k in [1..11] ];

Crossrefs

Cf. A127330, A129143.

Sequence in context: A109054 A350690 A363751 * A359749 A075752 A046541

Adjacent sequences: A129139 A129140 A129141 * A129143 A129144 A129145

Keyword

nonn,easy

Author

Klaus Brockhaus, Mar 31 2007

Status

approved