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.

Showing 1-10 of 10 results.

A276603 The infinite trunk of ternary beanstalk, terms divided by 2: a(n) = A276623(n) / 2.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 8, 10, 13, 14, 15, 17, 19, 21, 23, 26, 28, 31, 34, 36, 40, 41, 42, 44, 46, 48, 50, 53, 55, 58, 61, 63, 67, 70, 72, 76, 80, 82, 85, 88, 90, 94, 97, 99, 102, 106, 108, 112, 116, 121, 122, 123, 125, 127, 129, 131, 134, 136, 139, 142, 144, 148, 151, 153, 157, 161, 163, 166, 169, 171, 175, 178, 180, 183, 187, 189, 193, 197
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Crossrefs

Cf. A276623, A276605 (first differences).

Programs

Formula

a(n) = A276623(n) / 2.

A276604 After a(0)=0, the first differences of A276623.

Original entry on oeis.org

0, 2, 2, 4, 2, 2, 4, 4, 6, 2, 2, 4, 4, 4, 4, 6, 4, 6, 6, 4, 8, 2, 2, 4, 4, 4, 4, 6, 4, 6, 6, 4, 8, 6, 4, 8, 8, 4, 6, 6, 4, 8, 6, 4, 6, 8, 4, 8, 8, 10, 2, 2, 4, 4, 4, 4, 6, 4, 6, 6, 4, 8, 6, 4, 8, 8, 4, 6, 6, 4, 8, 6, 4, 6, 8, 4, 8, 8, 10, 6, 4, 6, 8, 4, 8, 8, 10, 8, 8, 10, 4, 6, 6, 4, 8, 6, 4, 6, 8, 4, 8, 8, 10, 6, 4, 6, 8, 4, 8, 8, 8, 8, 8, 10
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Crossrefs

Cf. A053735, A276623, A276605 (terms divided by 2).

Formula

a(n) = A053735(A276623(n)).
a(0) = 0; for n >= 1, a(n) = A276623(n) - A276623(n-1).

A179016 The infinite trunk of binary beanstalk: The only infinite sequence such that a(n-1) = a(n) - number of 1's in binary representation of a(n).

Original entry on oeis.org

0, 1, 3, 4, 7, 8, 11, 15, 16, 19, 23, 26, 31, 32, 35, 39, 42, 46, 49, 53, 57, 63, 64, 67, 71, 74, 78, 81, 85, 89, 94, 97, 101, 104, 109, 112, 116, 120, 127, 128, 131, 135, 138, 142, 145, 149, 153, 158, 161, 165, 168, 173, 176, 180, 184, 190, 193, 197, 200, 205, 209
Offset: 0

Views

Author

Carl R. White, Jun 24 2010

Keywords

Comments

a(n) tells in what number we end in n steps, when we start climbing up the infinite trunk of the "binary beanstalk" from its root (zero). The name "beanstalk" is due to Antti Karttunen.
There are many finite sequences such as 0,1,2; 0,1,3,4,7,9; etc. obeying the same condition (see A218254) and as the length increases, so (necessarily) does the similarity to this infinite sequence.

Crossrefs

A subsequence of A005187, i.e., a(n) = A005187(A213715(n)). For all n,
A071542(a(n)) = n, and furthermore A213708(n) <= a(n) <= A173601(n). (Cf. A218603, A218604).
Rows of A218254, when reversed, converge towards this sequence.
Cf. A276623, A219648, A219666, A255056, A276573, A276583, A276613 for analogous constructions, and also A259934.

Programs

  • Mathematica
    TakeWhile[Reverse@ NestWhileList[# - DigitCount[#, 2, 1] &, 10^3, # > 0 &], # <= 209 &] (* Michael De Vlieger, Sep 12 2016 *)

Formula

a(0)=0, a(1)=1, and for n > 1, if n = A218600(A213711(n)) then a(n) = (2^A213711(n)) - 1, and in other cases, a(n) = a(n+1) - A213712(n+1). (This formula is based on Carl White's observation that this iterated/converging path must pass through each (2^n)-1. However, it would be very interesting to know whether the sequence admits more traditional recurrence(s), referring to previous, not to further terms in the sequence in their definition!) - Antti Karttunen, Oct 26 2012
a(n) = A218616(A218602(n)). - Antti Karttunen, Mar 04 2013
a(n) = A054429(A233271(A218602(n))). - Antti Karttunen, Dec 12 2013

Extensions

Starting offset changed from 1 to 0 by Antti Karttunen, Nov 05 2012

A276573 The infinite trunk of least squares beanstalk: The only infinite sequence such that a(0) = 0 and a(n-1) = a(n) - least number of squares (A002828) that sum to a(n).

Original entry on oeis.org

0, 3, 6, 8, 11, 15, 16, 18, 21, 24, 27, 30, 32, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 63, 64, 67, 70, 72, 75, 78, 80, 83, 85, 88, 90, 93, 96, 99, 102, 105, 108, 112, 115, 117, 120, 123, 126, 128, 131, 134, 136, 139, 143, 144, 147, 149, 152, 155, 158, 160, 162, 165, 168, 171, 173, 176, 179, 183, 186, 189, 192, 195
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Crossrefs

Cf. A002828, A005563, A255131, A260731, A260733, A262689, A276572, A276574, A276575 (first differences), A277016 (squares present), A277015 (their square roots), A277888 (primes), A278486 (numbers one more than a prime), A278265, A278487, A278488, A278491 (another subsequence), A278497, A278498, A278499, A278513, A278516, A278517, A278518, A278519, A278521, A278522.
Cf. A277890 & A277891 (number of even and odd terms in each range. The latter seem to be slightly more numerous), A277889.
Positions of nonzero terms in A278515.
Subsequence of A278489, no common terms with A278490.
Cf. also A179016, A259934, A276583, A276613, A276623 for similar constructions.

Programs

Formula

a(n) = A276574(A276572(n)).
Other identities and observations. For all n >= 0:
A260731(a(n)) = n.
a(A260733(n+1)) = A005563(n).
A278517(n) <= a(n) <= A278519(n).
A010873(a(n)) = A278499(n). [Terms reduced modulo 4.]
A010877(a(n)) = A278488(n). [modulo 8.]
A046523(a(n)) = A278497(n). [Least number with the same prime signature.]
A008683(a(n)) = A278513(n).
A065338(a(n)) = A278498(n).
A278509(a(n)) = A278265(n).
A278216(a(n)) = A278516(n). [Number of children the n-th node of the trunk has.]

Extensions

Definition clarified and more identities added to the Formula section by Antti Karttunen, Nov 28 2016

A276583 The infinite trunk of greedy squares beanstalk: The only infinite sequence such that a(n-1) = a(n) - number of squares that sum to a(n) with greedy algorithm (A053610).

Original entry on oeis.org

0, 3, 6, 8, 11, 15, 18, 21, 24, 27, 32, 35, 38, 43, 48, 51, 56, 59, 63, 66, 71, 74, 78, 80, 83, 88, 91, 95, 99, 102, 107, 110, 114, 117, 120, 123, 128, 131, 135, 138, 143, 146, 151, 154, 158, 161, 164, 168, 171, 176, 179, 183, 186, 192, 195, 198, 203, 206, 210, 213, 219, 224, 227, 232, 235, 239, 242, 248, 251, 255
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Crossrefs

Cf. A053610, A260740, A276582, A276584, A276585 (first differences).
Cf. also A179016, A259934, A276573, A276613, A276623 for similar constructions.

Programs

Formula

a(n) = A276584(A276582(n)).

A276613 The infinite trunk of greedy cubes beanstalk: The only infinite sequence such that a(n-1) = a(n) - number of cubes that sum to a(n) with greedy algorithm (A055401).

Original entry on oeis.org

0, 7, 14, 21, 26, 33, 40, 47, 52, 59, 63, 70, 77, 84, 89, 96, 103, 110, 115, 124, 131, 138, 145, 150, 157, 164, 171, 176, 183, 187, 194, 201, 208, 215, 222, 229, 236, 241, 248, 255, 262, 267, 274, 278, 285, 292, 299, 304, 311, 318, 330, 339, 342, 349, 356, 363, 368, 375, 382, 389, 394, 401, 405, 412, 419, 426, 431, 438, 445
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Crossrefs

Cf. A055401, A261225, A276612, A276614, A276615 (first differences).
Cf. also A179016, A259934, A276573, A276583, A276623 for similar constructions.

Programs

Formula

a(n) = A276614(A276612(n)).

A276605 After a(0)=0, the first differences of A276603.

Original entry on oeis.org

0, 1, 1, 2, 1, 1, 2, 2, 3, 1, 1, 2, 2, 2, 2, 3, 2, 3, 3, 2, 4, 1, 1, 2, 2, 2, 2, 3, 2, 3, 3, 2, 4, 3, 2, 4, 4, 2, 3, 3, 2, 4, 3, 2, 3, 4, 2, 4, 4, 5, 1, 1, 2, 2, 2, 2, 3, 2, 3, 3, 2, 4, 3, 2, 4, 4, 2, 3, 3, 2, 4, 3, 2, 3, 4, 2, 4, 4, 5, 3, 2, 3, 4, 2, 4, 4, 5, 4, 4, 5, 2, 3, 3, 2, 4, 3, 2, 3, 4, 2, 4, 4, 5, 3, 2, 3, 4, 2, 4, 4, 4, 4, 4, 5, 2, 4, 4, 4, 4, 4, 5
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Crossrefs

Formula

a(n) = A276604(n) / 2.
a(0) = 0; for n >= 1, a(n) = A276603(n) - A276603(n-1).

A276622 Simple self-inverse permutation of natural numbers: after a(0)=0, list each block of A261234(n) numbers in reverse order, from A261232(n) to A261233(1+n).

Original entry on oeis.org

0, 1, 3, 2, 8, 7, 6, 5, 4, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 123, 122, 121, 120, 119, 118, 117, 116, 115, 114, 113, 112, 111, 110, 109, 108, 107, 106, 105, 104, 103, 102, 101, 100, 99, 98, 97, 96
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Comments

Maps between A276623 and A276624.

Crossrefs

Programs

Formula

a(0) = 0; for n >= 1, a(n) = A261232(A276621(n)-1) + A261232(A276621(n)) - n - 1.

A276624 The infinite trunk of ternary beanstalk with reversed subsections.

Original entry on oeis.org

0, 2, 8, 4, 26, 20, 16, 12, 10, 80, 72, 68, 62, 56, 52, 46, 42, 38, 34, 30, 28, 242, 232, 224, 216, 212, 204, 198, 194, 188, 180, 176, 170, 164, 160, 152, 144, 140, 134, 126, 122, 116, 110, 106, 100, 96, 92, 88, 84, 82, 728, 716, 706, 698, 688, 680, 672, 664, 656, 648, 644, 634, 626, 618, 610, 602, 594, 590, 582, 576, 572
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Comments

See A276623.

Crossrefs

Programs

  • Scheme
    (definec (A276624 n) (cond ((zero? n) n) ((= n 1) 2) (else (let ((maybe_next (* 2 (A054861 (A276624 (- n 1)))))) (if (not (= 1 (A053735 (+ 1 maybe_next)))) maybe_next (+ -1 (A000244 (+ 1 (A081604 (+ 1 maybe_next))))))))))

Formula

a(0) = 0; a(1) = 2; for n > 1, if 2*A054861(a(n-1))+1 is not a power of 3, then a(n) = 2*A054861(a(n-1)), otherwise a(n) = A000244(1+A081604(1+2*A054861(a(n-1)))) - 1.

A276621 After a(0)=0, each n occurs A261234(n-1) times.

Original entry on oeis.org

0, 1, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Comments

Auxiliary function for computing A276622 & A276623.

Crossrefs

After a(0), a(n) differs from A111393(n+1) for the first time at n=46, where a(46)=5, while A111393(47)=6.

Programs

  • Scheme
    (define (A276621 n) (let loop ((k 0)) (if (>= (A261233 k) n) k (loop (+ 1 k)))))
Showing 1-10 of 10 results.