cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A141439 Positions at which disjoint pattern counts differ from overlapping pattern counts related to sequence A117127.

Original entry on oeis.org

21, 22, 23, 45, 47, 55, 73, 85, 86, 90, 91, 95, 109, 110, 111, 119, 146, 170, 173, 181, 182, 187, 191, 219, 221, 223, 239, 247, 273, 307, 341, 342, 346, 362, 365, 375, 383, 409, 438, 443, 447, 477, 478, 479, 495, 503, 546, 585, 614, 660, 682, 685, 693, 725
Offset: 1

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Author

Diana L. Mecum, Aug 06 2008

Keywords

Examples

			When "n" = 21, the base two concatenated range of integers from 1 to 21 is "1101110010111011110001001101010111100110111101111100001000110010100111010010101". 21 in base two is "10101".
Note that there are two instances of "10101" in the concatenated number when disjoint patterns are considered. There are three pattern matches when overlapping patterns are considered.
		

Crossrefs

Cf. A117127.

Programs

  • Mathematica
    f[n_, k_] := StringCount[ ToString@ FromDigits@ Flatten@ IntegerDigits[ Range@n, 2], ToString@ FromDigits@ IntegerDigits[n, 2], Overlaps -> {True, False}[[k]]]; Select[ Range@ 725, f[ #, 1] != f[ #, 2] &] (* Robert G. Wilson v, Aug 30 2008 *)

A101933 Concatenate the first n positive integers written in binary (with each integer written so the most significant 1 is on the left and the concatenated string is from left to right, A030302). a(n) is the number of times n written in binary appears disjointedly in the concatenated string.

Original entry on oeis.org

1, 1, 2, 1, 2, 3, 3, 1, 2, 1, 4, 3, 4, 5, 4, 1, 2, 2, 3, 2, 2, 1, 6, 3, 4, 4, 6, 6, 5, 7, 5, 1, 2, 2, 3, 1, 4, 3, 4, 2, 4, 2, 5, 2, 3, 4, 8, 3, 4, 5, 5, 4, 6, 4, 8, 6, 6, 6, 7, 9, 6, 9, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 2, 3, 5, 2, 6, 4, 5, 2, 4, 3, 6, 3, 3, 3, 7, 2, 5, 3, 5, 3, 7, 5, 10, 3, 4, 5, 5, 4, 7, 5, 7, 4, 6
Offset: 1

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Author

Keywords

Comments

First occurrence of n: 1, 3, 6, 11, 14, 23, 30, 47, 60, 95, 126, 124, 223, 248, 252, 447, 863, 504, 895, 1008, 1020, 1016, 1919, 2044, 2032, 2040, 3839, 7159, 7871, 4080, 7679, 15855, 8160, 8184, 8176, 15839, ??, 16376, 16352, 16368, ..., to a limit of 25000.

Examples

			a(21) = 2 because 21_10 = 10101_2 and that appears in
1101110010111011110001001101010111100110111101111100001000110010100111010010101_2
three times but only two times which do not overlap.
		

Crossrefs

Cf. A007088, A030190, A030302, A058935, A047778. Differs from A117127 at positions in A141439.

Programs

  • Mathematica
    a[n_] := StringCount[ ToString@ FromDigits@ Flatten@ IntegerDigits[ Range@n, 2], ToString@ FromDigits@ IntegerDigits[n, 2], Overlaps -> False]; Array[a, 105]
Showing 1-2 of 2 results.