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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A277119 Numbers n such that A277118(n) = 17.

Original entry on oeis.org

470, 746, 995, 3061, 3425, 3486, 11359, 12233, 16181, 17142, 18717, 24976, 30991, 48138, 61882, 62293, 63833, 99770, 103132, 110651, 111769, 112407, 117282, 138939, 149251, 150296, 161457, 173581, 174029, 176096, 188691, 221737, 225322, 233565, 235084, 237651, 262176, 266889, 279382, 281398, 284617, 290328, 292830
Offset: 1

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Comments

A277118 takes only the values 0, 3, 5, 7, 9, 11, 13, 15, and 17, so these are the indices of maximal terms in A277118.
Let p=A001359(n-1). Then n is in the sequence if and only if we have seven consecutive primes: either {p=30t+29 (t>=0),p+2,p+8,p+12,p+18,p+24,p+30} or {p,p+2,p+8,p+14,p+20,p+24,p+30} or {p,p+2,p+8,p+14,p+18,p+24,p+30}, but p+32 is composite. In the case, when also p+32 is prime, the numbers
{n} form sequence A277512.

Examples

			a(1)=470, then we have seven primes: p=A001359(469) =30089, 30091, 30097, 30103,30109,30113,30119, but 30121 is composite (cf. comment).
		

Crossrefs

A277512 Numbers n such that A277118(n) = 15.

Original entry on oeis.org

13, 88, 5708, 15095, 18300, 20718, 23424, 45625, 59638, 63958, 66438, 71747, 78239, 154992, 225235, 411285, 418434, 550190, 571439, 743873, 883958, 938420, 989479, 1169298, 1198004, 1256049
Offset: 1

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Let p=A001359(n-1). Then n is in the sequence if and only if we have one of constellations of eight consecutive primes: {p=30t+29 (t>=0), p+2,p+8, p+12,p+18, p+24,p+30,p+32}, {p,p+2,p+8,p+14,p+20,p+24,p+30,p+32}, {p,p+2, p+8,p+14, p+18,p+24,p+30,p+32}.

Examples

			a(1)=13, then we have one of three mentioned in comment constellations of 8 consecutive primes: p=A001359(12)=149, 151, 157, 163, 167, 173, 179 and 181.
		

Crossrefs

A277255 Let A_n defined in the same way as A159559, but with initial term prime(n); a(n) is the smallest number m such that A_(n+1)(m) - A_n(m) > 6 or a(n)=0 if there is no such m.

Original entry on oeis.org

0, 13, 0, 0, 9, 0, 0, 13, 0, 15, 0, 9, 0, 0, 11, 0, 17, 13, 11, 7, 5, 3, 2, 0, 11, 7, 5, 3, 2, 7, 5, 3, 2, 15, 0, 9, 0, 7, 5, 3, 2, 7, 5, 3, 2, 2, 9, 0, 7, 5, 3, 2, 0, 0, 11, 0, 7, 5, 3, 2, 2, 7, 5, 3, 2, 3, 2, 7, 5, 3, 2, 11, 7, 5, 3, 2, 3, 2, 2, 3, 2, 11, 7
Offset: 2

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A277118 is a subsequence. In contrast to A277118, the sequence contains some terms greater than 17. The first occurrence for 19 is n = 7061; the first occurrence for 21 is n = 214612 and the first occurrence for 23 is n = 30572.

Crossrefs

Formula

a(n)=2 if and only if prime(n+1) - prime(n) >=8.
Showing 1-3 of 3 results.