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.

A380139 Prime gaps between 10^m and 10^(m+1), m>=0, sorted first by falling number of occurrences and then by rising gap size, written as an irregular triangle.

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%I A380139 #16 Jan 26 2025 09:08:38
%S A380139 2,1,4,4,6,2,8,6,4,2,10,8,12,14,18,20,6,2,4,10,12,8,14,18,16,22,24,20,
%T A380139 30,28,26,34,32,36,6,2,4,12,10,8,18,14,16,20,22,24,30,28,26,36,32,34,
%U A380139 40,38,42,52,44,50,46,54,58,48,56,60,62,64,72
%N A380139 Prime gaps between 10^m and 10^(m+1), m>=0, sorted first by falling number of occurrences and then by rising gap size, written as an irregular triangle.
%C A380139 A gap between two primes p1 and p2 is assumed to belong to the range [10^m .. 10^(m+1)[ if 10^m <= (p1+p2)/2 < 10^(m+1). Thus the gap between 7 and 11 is counted in the interval 1 .. 10. Gaps symmetric to 10^k occur for k = 17, 45, ... .
%H A380139 Hugo Pfoertner, <a href="/A380139/b380139.txt">Table of n, a(n) for n = 1..583</a>
%e A380139 The triangle begins, with corresponding counts in [...]:
%e A380139   [2, 1, 1]
%e A380139    2, 1, 4,
%e A380139   [7, 7, 6, 1]
%e A380139    4, 6, 2, 8,
%e A380139   [37, 32, 27, 16, 14,  8,  7,  1,  1]
%e A380139     6,  4,  2, 10,  8, 12, 14, 18, 20
%e A380139   [255, 170, 162, 103, 98, 86, 47, 39, 33, 16, 15, 14, 11,  5,  3,  3,  1,  1]
%e A380139     6,   2,   4,   10, 12,  8, 14, 18, 16, 22, 24, 20, 30, 28, 26, 34, 32, 36,
%e A380139   [1641, 1018, 1013, 860, 797, 672, 474, 430, 306, 223, 207, 191, 135, 93, 85, ...]
%e A380139      6,    2,    4,   12,  10,  8,   18,  14,  16,  20,  22,  24,  30, 28, 26, ...
%e A380139   [11609, 7040, 6945, 6928, 6163, 4796, 4395, 3749, 2542, 2476, 2164, 1949, ...]
%e A380139      6,    12,    2,    4,   10,    8,   18,   14,   16,   24,   20,   22,  ...
%e A380139   6, 12, 2, 4, 10, 18, 8, 14, 24, 16, 30, 20, 22, 28, 26, 36, 42, 34, ...
%e A380139   6, 12, 4, 2, 10, 18, 8, 14, 24, 30, 16, 20, 22, 28, 26, 36, 42, 34, ...
%e A380139   6, 12, 10, 4, 2, 18, 8, 14, 24, 30, 16, 20, 22, 28, 36, 26, 42, 34, ...
%e A380139   6, 12, 18, 10, 2, 4, 8, 24, 30, 14, 20, 16, 22, 36, 28, 26, 42, 34, ...
%Y A380139 Cf. A001223, A028334, A038460, A354604.
%Y A380139 Cf. A005597, A173557, A305444 for the asymptotic behavior of gap sizes.
%K A380139 nonn,tabf
%O A380139 1,1
%A A380139 _Hugo Pfoertner_ based on an idea by _Richard Stephen Donovan_, Jan 23 2025