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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A095759 Triangle T(row>=0, 0<= pos <=row) by rows: T(r,p) contains number of odd primes p in range [2^(r+1),2^(r+2)] for which A037888(p)=pos.

Original entry on oeis.org

1, 2, 0, 0, 2, 0, 2, 3, 0, 0, 0, 5, 2, 0, 0, 3, 4, 6, 0, 0, 0, 0, 15, 4, 4, 0, 0, 0, 3, 18, 15, 7, 0, 0, 0, 0, 0, 32, 20, 16, 7, 0, 0, 0, 0, 7, 33, 63, 24, 10, 0, 0, 0, 0, 0, 0, 63, 62, 88, 33, 9, 0, 0, 0, 0, 0, 12, 81, 135, 154, 56, 26, 0, 0, 0, 0, 0, 0, 0, 119, 150, 314, 197, 72, 20, 0, 0, 0, 0, 0, 0
Offset: 0

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Author

Antti Karttunen, Jun 12 2004

Keywords

Examples

			a(0) = T(0,0) = 1 as there is one prime 3 (11 in binary) in range ]2^1,2^2[ whose binary expansion is palindromic. a(1) = T(1,0) = 2 as there are two primes, 5 and 7 (101 and 111 in binary) in range ]2^2,2^3[ whose binary expansions are palindromic. a(2) = T(1,1) = 0, as there are no other primes in that range. a(3) = T(2,0) = 0, as there are no palindromic primes in range ]2^3,2^4[, but a(4) = T(2,1) = 2 as in the same range there are two primes 11 and 13 (1011 and 1101 in binary), whose binary expansion needs a flip of just one bit to become palindrome.
		

Crossrefs

Row sums: A036378. Bisection of the leftmost diagonal: A095741. Next diagonals: A095753, A095754, A095755, A095756. Central diagonal (column): A095760. The rightmost nonzero terms from each row: A095757 (i.e. central diagonal and next-to-central diagonal interleaved). The penultimate nonzero terms from each row: A095758. Cf. also A095749, A048700-A048704, A095742.

A095753 Number of almost base-2 palindromic primes (A095743) in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 2, 3, 5, 4, 15, 18, 32, 33, 63, 81, 119, 144, 256, 318, 527, 640, 1029, 1281, 2236, 2566, 4273, 5410, 8261, 10610, 16868, 21084, 33943, 43104, 68218, 88493, 136343
Offset: 1

Views

Author

Antti Karttunen, Jun 12 2004

Keywords

Comments

Ratio a(n)/A036378(n) converges as follows: 0, 0, 1, 0.6, 0.714286, 0.307692, 0.652174, 0.418605, 0.426667, 0.240876, 0.247059, 0.174569, 0.136468, 0.08933, 0.084488, 0.055702, 0.049028, 0.031388, 0.026634, 0.017408, 0.015933, 0.009567, 0.008318, 0.005488, 0.004361, 0.00291, 0.0024, 0.001555, 0.001295, 0.00085, 0.000695, 0.000465, 0.000369
Ratio a(n)/A095758(n) converges as follows: 1, 1, 0, 1.5, 1, 1, 3.75, 1.2, 2, 1.375, 1.909091, 1.446429, 1.652778, 1.515789, 1.718121, 1.452055, 1.636646, 1.191806, 1.570992, 1.283567, 1.708174, 1.380312, 1.534842, 1.392177, 1.547004, 1.311334, 1.573801, 1.302205, 1.521016, 1.419202, 1.570938, 1.389237, 1.546084

Crossrefs

The second diagonal of triangle A095759. Cf. A095742.

A095732 Sum of A095734(p) for all primes p such that Fib(n+1) <= p < Fib(n+2) (where Fib = A000045).

Original entry on oeis.org

0, 0, 1, 3, 1, 3, 7, 10, 12, 23, 31, 58, 93, 171, 243, 422, 634, 1142, 1684, 2971, 4406, 7768, 11502, 20502, 30242, 53039, 79161, 138410, 207536, 362391, 544895, 947189, 1431794, 2473232, 3749944, 6459373, 9823917, 16879245, 25745781, 44112347
Offset: 1

Views

Author

Antti Karttunen, Jun 12 2004

Keywords

Comments

Ratio a(n)/A095354(n) converges as follows: 1, 1, 1, 1.5, 1, 1, 2.333333, 2, 1.714286, 2.090909, 1.9375, 2.416667, 2.513514, 3.109091, 2.892857, 3.349206, 3.20202, 3.845118, 3.676856, 4.22017, 4.053358, 4.640382, 4.420446, 5.088608, 4.828676, 5.446601, 5.212762, 5.838853, 5.611963, 6.257939, 6.017615, 6.668795, 6.424778, 7.069164, 6.819283, 7.467319, 7.215081, 7.868411, 7.614126, 8.269242

Examples

			a(1) = a(2) = 0, as there are no primes in ranges [1,2[ and [2,3[. a(3)=1 as in [3,5[ there is prime 3 with Fibonacci-representation 100, which is just a one fibit-flip away from being a palindrome (i.e. A095734(3)=1). a(4)=3, as in [5,8[ there are primes 5 and 7, whose Fibonacci-representations are 1000 and 1010 respectively and the other needs one bit-flip and the other two to become palindromes and 1 + 2 = 3. a(5)=1, as in [8,13[ there is only one prime 11, with Zeckendorf-representation 10100, which needs to have just its least significant fibit flipped from 0 to 1 to become palindrome.
		

Crossrefs

Cf. A095730, A095731, A095742 (sums of similar assymetricity measures for binary-expansion).

A095758 Number of A095748-primes in range ]2^n,2^(n+1)].

Original entry on oeis.org

0, 0, 0, 2, 5, 4, 4, 15, 16, 24, 33, 56, 72, 95, 149, 219, 322, 537, 655, 998, 1309, 1859, 2784, 3886, 5340, 8091, 10718, 16191, 22316, 30372, 43425, 63699, 88186
Offset: 1

Views

Author

Antti Karttunen, Jun 12 2004

Keywords

Comments

Ratio a(n)/A036378(n) converges as follows: 0, 0, 0, 0.4, 0.714286, 0.307692, 0.173913, 0.348837, 0.213333, 0.175182, 0.129412, 0.12069, 0.082569, 0.058933, 0.049175, 0.03836, 0.029956, 0.026336, 0.016954, 0.013562, 0.009328, 0.006931, 0.005419, 0.003942, 0.002819, 0.002219, 0.001525, 0.001194, 0.000852, 0.000599, 0.000442, 0.000335, 0.000239
Ratio a(n)/A095753(n) converges as follows: 1, 1, 0, 0.666667, 1, 1, 0.266667, 0.833333, 0.5, 0.727273, 0.52381, 0.691358, 0.605042, 0.659722, 0.582031, 0.688679, 0.611006, 0.839063, 0.63654, 0.779079, 0.58542, 0.724474, 0.651533, 0.718299, 0.646411, 0.762582, 0.635404, 0.767928, 0.657455, 0.704621, 0.636562, 0.71982, 0.646795

Crossrefs

The penultimate nonzero terms from each row of triangle A095759. Cf. A095757, A095742.
Showing 1-4 of 4 results.