A117351 - OEIS

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A117351

Where n appears in A082224, provided A082224 is read as a sequence rather than as an array.

1, 2, 3, 4, 11, 7, 10, 5, 22, 6, 37, 8, 21, 14, 9, 17, 55, 13, 56, 16, 36, 15, 78, 12, 79, 20, 105, 19, 106, 18, 136, 35, 137, 26, 172, 24, 171, 25, 211, 23, 210, 28, 253, 27, 254, 29, 300, 31, 301, 34, 351, 30, 352, 32, 407, 39, 406, 38, 465, 33, 466, 43, 529, 40, 528, 41

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Conjecture: Sequence is a permutation of the positive integers.

LINKS

Table of n, a(n) for n=1..66.

EXAMPLE

A082224(11) = 5, hence a(5) = 11.

PROG

(PARI) lista(nn) = { A=matrix(nn, nn); my(b=vector(nn^2)); S=Set(); for(s=2, nn+1, for(i=1, s-1, if(s%2, q=[i, s-i], q=[s-i, i]); p=[sum(j=1, q[2]-1, A[q[1], j]), sum(j=1, q[1]-1, A[j, q[2]])]; n=1; while(setsearch(S, n) || (p[1]&&!isprime(p[1]+n)) || (p[2]&&isprime(p[2]+n)), n++); A[q[1], q[2]]=n; S=setunion(S, Set([n])); mm=(q[1]+q[2]-1)*(q[1]+q[2]-2)/2 + q[2]*(1 + (-1)^(q[1]+q[2]))/2 + q[1]*(1 - (-1)^(q[1]+q[2]))/2; b[n]=mm; )); for(ii=1, nn^2, if (b[ii], print1(b[ii], ", "), break)); } \\ If the desired a(n) does not appear in the output, then one needs to increase the value of nn in lista(nn) until a(n) appears. This program is a modification of the PARI program by Max Alekseyev in A082228. - Petros Hadjicostas, Feb 25 2021

CROSSREFS

Cf. A082224, A082228.

Sequence in context: A325692 A075833 A265904 * A343602 A357530 A108467

Adjacent sequences: A117348 A117349 A117350 * A117352 A117353 A117354

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Mar 09 2006

STATUS

approved