The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A049967 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A049967

a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 1.
(history; published version)

#17 by N. J. A. Sloane at Fri May 06 13:12:16 EDT 2022

CROSSREFS

Cf. A049918 (similar, but with minus a(m/2)), A049919 (similar, but with minus a(m)), A049966 (similar , but with plus a(m/2)).

Discussion

Fri May 06

13:12

OEIS Server: https://oeis.org/edit/global/2940

#16 by N. J. A. Sloane at Fri May 06 13:11:36 EDT 2022

CROSSREFS

Cf. A049918 (similar , but with minus a(m/2)), A049919 (similar , but with minus a(m)), A049966 (similar with plus a(m/2)).

Discussion

Fri May 06

13:11

OEIS Server: https://oeis.org/edit/global/2939

#15 by Alois P. Heinz at Sun May 03 16:23:12 EDT 2020

STATUS

proposed

approved

#14 by Petros Hadjicostas at Sun May 03 15:55:02 EDT 2020

STATUS

editing

proposed

#13 by Petros Hadjicostas at Sun May 03 15:44:19 EDT 2020

PROG

(PARI) slista(nn) = { nn = max(nn, 3); my(va = vector(nn)); va[1] = 1; va[2] = 3; va[3] = 1; my(sa = vecsum(va)); for (n) = {if4, nn, va[n] = sa + va[2*(n< - 1, 0 - 2^logint(n-2, 2))]; sa += va[n]; ); va; } \\ _Petros Hadjicostas_, May 03 2020

if(s_table == 's_table, s_table = [1]);

if(#s_table < n, s_table=concat(s_table, vector(n-#s_table)));

if(s_table[n], s_table[n], s_table[n] = s(n-1)+a(n))}

m(n)={if(n<2, 0, -2^ceil(log(n-1)/log(2)) + 2*n - 2)}

a(n)={if(n<=3, return(2+(-1)^n));

if(a_table == 'a_table, a_table = [1]);

if(#a_table < n, a_table=concat(a_table, vector(n-#a_table)));

if(a_table[n], a_table[n], a_table[n] = s(n-1) + a(m(n)))}

for(n=1, 40, print1(a(n), ", ")); \\ Petros Hadjicostas, Apr 24 2020

CROSSREFS

Cf. A049918 (similar with minus a(m/2)), A049919 (similar with minus a(m)), A049966 (similar with plus a(m/2)).

STATUS

approved

editing

#12 by Michel Marcus at Sat Apr 25 01:40:10 EDT 2020

STATUS

reviewed

approved

#11 by Joerg Arndt at Sat Apr 25 01:16:39 EDT 2020

STATUS

proposed

reviewed

#10 by Petros Hadjicostas at Fri Apr 24 21:26:59 EDT 2020

STATUS

editing

proposed

#9 by Petros Hadjicostas at Fri Apr 24 21:24:00 EDT 2020

PROG

a(n)={if(n<=3, return(2^+(n-1)^n));

#8 by Petros Hadjicostas at Fri Apr 24 21:21:36 EDT 2020

PROG

m(n)={if(n<2, 0, -2^ceil(-1+log(n-1)/log(2)) + 2*n - 12)}