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 1-8 of 8 results.

A276615 After a(0)=0, the first differences of A276613.

Original entry on oeis.org

0, 7, 7, 7, 5, 7, 7, 7, 5, 7, 4, 7, 7, 7, 5, 7, 7, 7, 5, 9, 7, 7, 7, 5, 7, 7, 7, 5, 7, 4, 7, 7, 7, 7, 7, 7, 7, 5, 7, 7, 7, 5, 7, 4, 7, 7, 7, 5, 7, 7, 12, 9, 3, 7, 7, 7, 5, 7, 7, 7, 5, 7, 4, 7, 7, 7, 5, 7, 7, 12, 9, 7, 7, 7, 5, 7, 7, 5, 7, 7, 7, 5, 7, 7, 7, 5, 7, 4, 7, 7, 7, 5, 7, 7, 12, 9, 7, 7, 7, 5, 7, 7, 12, 11, 7, 7, 7, 7, 2
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Crossrefs

Formula

a(n) = A055401(A276613(n)).
a(0) = 0; for n >= 1, a(n) = A276613(n) - A276613(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

A276623 The infinite trunk of ternary beanstalk: The only infinite sequence such that a(n-1) = a(n) - A053735(a(n)), where A053735(n) = base-3 digit sum of n.

Original entry on oeis.org

0, 2, 4, 8, 10, 12, 16, 20, 26, 28, 30, 34, 38, 42, 46, 52, 56, 62, 68, 72, 80, 82, 84, 88, 92, 96, 100, 106, 110, 116, 122, 126, 134, 140, 144, 152, 160, 164, 170, 176, 180, 188, 194, 198, 204, 212, 216, 224, 232, 242, 244, 246, 250, 254, 258, 262, 268, 272, 278, 284, 288, 296, 302, 306, 314, 322, 326, 332, 338, 342, 350, 356, 360
Offset: 0

Views

Author

Antti Karttunen, Sep 11 2016

Keywords

Crossrefs

Cf. A004128, A024023, A053735, A054861, A261231 (left inverse), A261233, A276622, A276624, A276603 (terms divided by 2), A276604 (first differences).
Cf. A179016, A219648, A219666, A255056, A259934, A276573, A276583, A276613 for similar constructions.
Cf. also A263273.

Programs

Formula

a(n) = A276624(A276622(n)).
Other identities. For all n >= 0:
A261231(a(n)) = n.
a(A261233(n)) = A024023(n) = 3^n - 1.

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)).

A276612 Simple self-inverse permutation of natural numbers: after a(0)=0, list each block of A261229(n) numbers in reverse order, from A261227(n) to A261228(1+n).

Original entry on oeis.org

0, 1, 4, 3, 2, 10, 9, 8, 7, 6, 5, 19, 18, 17, 16, 15, 14, 13, 12, 11, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 108
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Comments

Maps between A276613 and A276614.

Crossrefs

Programs

A276614 The infinite trunk of greedy cubes beanstalk with reversed subsections.

Original entry on oeis.org

0, 7, 26, 21, 14, 63, 59, 52, 47, 40, 33, 124, 115, 110, 103, 96, 89, 84, 77, 70, 215, 208, 201, 194, 187, 183, 176, 171, 164, 157, 150, 145, 138, 131, 342, 339, 330, 318, 311, 304, 299, 292, 285, 278, 274, 267, 262, 255, 248, 241, 236, 229, 222, 511, 506, 499, 492, 487, 480, 473, 466, 457, 445, 438, 431, 426, 419, 412, 405, 401
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016 and Sep 09 2016

Keywords

Crossrefs

Programs

  • Scheme
    (definec (A276614 n) (cond ((zero? n) n) ((= n 1) 7) (else (let ((maybe_next (A261225 (A276614 (- n 1))))) (if (zero? (A010057 (+ 1 maybe_next))) maybe_next (+ -1 (A000578 (+ 2 (A048766 (+ 1 maybe_next))))))))))

Formula

a(0) = 0; a(1) = 7; for n > 1, if A261225(a(n-1))+1 is not a cube, then a(n) = A261225(a(n-1)), otherwise a(n) = A000578(2+A048766(A261225(a(n-1)))) - 1.

A276611 After a(0)=0, each n occurs A261229(n) times.

Original entry on oeis.org

0, 1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 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, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2016

Keywords

Comments

Auxiliary function for computing A276612 & A276613.

Crossrefs

Programs

  • Scheme
    (define (A276611 n) (let loop ((k 0)) (if (>= (A261228 (+ 1 k)) n) k (loop (+ 1 k)))))
Showing 1-8 of 8 results.